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PubMed2006

Emerging infectious determinants of chronic diseases.

Evidence now confirms that noncommunicable chronic diseases can stem from infectious agents. Furthermore, at least 13 of 39 recently described infectious agents induce chronic syndromes. Identifying the relationships can affect health across populations, creating opportunities to reduce the impact of chronic disease by preventing or treating infection. As the concept is progressively accepted, advances in laboratory technology and epidemiology facilitate the detection of noncultivable, novel, and even recognized microbial origins. A spectrum of diverse pathogens and chronic syndromes emerges, with a range of pathways from exposure to chronic illness or disability. Complex systems of changing human behavioral traits superimposed on human, microbial, and environmental factors often determine risk for exposure and chronic outcome. Yet the strength of causal evidence varies widely, and detecting a microbe does not prove causality. Nevertheless, infectious agents likely determine more cancers, immune-mediated syndromes, neurodevelopmental disorders, and other chronic conditions than currently appreciated.

Bacterial Infections↗

PubMed2002

Population changes in a biofilm reactor for phosphorus removal as evidenced by the use of FISH.

Induction of denitrification was investigated for a lab-scale phosphate removing biofilm reactor where oxygen was replaced with nitrate as the electron acceptor. Acetate was used as the carbon source. The original biofilm (acclimatised with oxygen) was taken from a well-established large-scale reactor. During the first run, a decrease in the denitrifying bio-P activity was observed after 1 month following a change in the anaerobic phase length. This was initially interpreted as a shift in the microbial population caused by the changed operation. In the second run, biomass samples were regularly collected and analysed by fluorescent in situ hybridisation (FISH) and confocal laser scanning microscopy (CLSM). Concurrently, samples were taken from the original reactor with oxygen as electron acceptor in order to investigate natural microbial fluctuations. A similar decrease in the activity as in the first run was seen after one month, although the phase lengths had not been varied. Hence, the decrease after 1 month in the first and second run should be seen as a start-up phenomenon. FISH could detect a noticeable shift in the microbial population mainly within the first 2 weeks of operation. Almost all bacteria belonging to the alpha subclass disappeared and characteristic clusters of the beta and gamma subclasses were lost. Small clusters of gram-positive bacteria with a high DNA G + C content (GPBHGC) were gradually replaced by filamentous GPBHGC. Most of the bacteria in the denitrifying, phosphate removing biofilm belonged to the beta subclass of Proteobacteria. The applied set of gene probes had been selected based on existing literature on biological phosphate removing organisms and included a recently published probe for a Rhodocyclus-like clone. However, none of the specific probes hybridised to the dominant bacterial groups in the reactors investigated. No noticeable changes were detected in the aerobic bench-scale reactor during this period, indicating that the observed changes in the lab-scale reactor were caused by the changed environment.

Acetates↗

PubMed2005

Toll-like receptors: sentinels of host defence against bacterial infection.

Innate immunity provides a first line of host defence against infection through microbial recognition and killing while simultaneously activating a definitive adaptive immune response. Toll-like receptors (TLRs) are principal mediators of rapid microbial recognition and function mainly by detection of structural patterns that do not exist in the host. TLR2 and TLR4 were the first members of this innate immune receptor family to be strongly implicated in antibacterial host defence. Following the initial description of the mammalian TLR family, susceptibility to infection with numerous human microbial pathogens has been intensively studied using mice with engineered deletions of each of these molecules. While it has become quite clear that TLR activation is necessary for optimal host defence, a comprehensive understanding of the mechanisms by which this family of pattern recognition receptors engages protective immunity, particularly the adaptive response, is still evolving.

Adaptor Proteins, Signal Transducing↗

PubMed1989

Detection of chitinase activity after polyacrylamide gel electrophoresis.

Commercial Streptomyces griseus and Serratia marcescens chitinases and purified wheat germ W1A and hen egg white lysozymes were subjected to polyacrylamide gel electrophoresis under native conditions at pH 4.3. After electrophoresis, an overlay gel containing 0.01% (W/V) glycol chitin as substrate was incubated in contact with the separation gel. Lytic zones were revealed by uv illumination with a transilluminator after staining for 5 min with 0.01% (W/V) Calcofluor white M2R. As low as 500 ng of purified hen egg lysozyme could be detected after 1 h incubation at 37 degrees C. One band was observed with W1A lysozyme and several bands with the commercial microbial chitinases. The same system was also used with native polyacrylamide gel electrophoresis at pH 8.9. Several bands were detected with the microbial chitinases. The same enzymes were also subjected to denaturing polyacrylamide gel electrophoresis in gradient gels containing 0.01% (W/V) glycol chitin. After electrophoresis, enzymes were renatured in buffered 1% (V/V) purified Triton X-100. Lytic zones were revealed by uv after staining with Calcofluor white M2R as for native gels. The molecular weights of chitinolytic enzymes could thus be directly estimated. In denaturing gels, as low as 10 ng of purified hen egg white lysozyme could be detected after 2 h incubation at 37 degrees C. Estimated molecular weights of St. griseus and Se. marcescens were between 24,000 and 72,000 and between 40,500 and 73,000, respectively. Some microbial chitinases were only resistant to denaturation with sodium dodecyl sulfate while others were resistant to sodium dodecyl sulfate and beta-mercaptoethanol.

Chitinases↗

PubMed2005

A new method to measure air-borne pyrogens based on human whole blood cytokine response.

Air-borne microorganisms, as well as their fragments and components, are increasingly recognized to be associated with pulmonary diseases, e.g. organic dust toxic syndrome, humidifier lung, building-related illness, "Monday sickness." We have previously described and validated a new method for the detection of pyrogenic (fever-inducing) microbial contaminations in injectable drugs, based on the inflammatory reaction of human blood to pyrogens. We have now adapted this test to evaluate the total inflammatory capacity of air samples. Air was drawn onto PTFE membrane filters, which were incubated with human whole blood from healthy volunteers inside the collection device. Cytokine release was measured by ELISA. The test detects endotoxins and non-endotoxins, such as fungal spores, Gram-positive bacteria and their lipoteichoic acid moiety and pyrogenic dust particles with high sensitivity, thus reflecting the total inflammatory capacity of a sample. When air from different surroundings such as working environments and animal housing was assayed, the method yielded reproducible data which correlated with other parameters of microbial burden tested. We further developed a standard material for quantification and showed that this assay can be performed with cryopreserved as well as fresh blood. The method offers a test to measure the integral inflammatory capacity of air-borne microbial contaminations relevant to humans. It could thus be employed to assess air quality in different living and work environments.

Air Microbiology↗

PubMed2004

spa typing method for discriminating among Staphylococcus aureus isolates: implications for use of a single marker to detect genetic micro- and macrovariation.

Strain typing of microbial pathogens has two major aims: (i). to index genetic microvariation for use in outbreak investigations and (ii). to index genetic macrovariation for use in phylogenetic and population-based analyses. Until now, there has been no clear indication that one genetic marker can efficiently be used for both purposes. Previously, we had shown that DNA sequence analysis of the protein A gene variable repeat region (spa typing) provides a rapid and accurate method to discriminate Staphylococcus aureus outbreak isolates from those deemed epidemiologically unrelated. Here, using the hypothesis that the genetic macrovariation within a low-level recombinogenic species would accurately be characterized by a single-locus marker, we tested whether spa typing could congruently index the extensive genetic variation detected by a whole-genome DNA microarray in a collection of 36 isolates, which was recovered from 10 countries on four continents over a period of four decades, that is representative of the breadth of diversity within S. aureus. Using spa and coa typing, pulsed-field gel electrophoresis (PFGE), and microarray and multilocus enzyme electrophoresis (MLEE) data in molecular epidemiologic and evolutionary analyses, we determined that S. aureus likely has a primarily clonal population structure and that spa typing can singly index genetic variation with 88% direct concordance with the microarray and can correctly assign isolates to phylogenetic lineages. spa typing performed better than MLEE, PFGE, and coa typing in discriminatory power and in the degree of agreement with the microarray at various phylogenetic depths. This study showed that genetic analysis of the repeat region of protein A comprehensively characterizes both micro- and macrovariation in the primarily clonal population structure of S. aureus.

Antigens, Bacterial↗

PubMed2006

Transgenic maize in the presence of ampicillin modifies the metabolic profile and microbial population structure of bovine rumen fluid in vitro.

Recently, transgenic crops have been considered as possible donors of transgenes that could be taken up by micro-organisms under appropriate conditions. In an in vitro rumen simulation system, effects of ampicillin on microbial communities growing either on rumen contents with transgenic maize carrying a gene that confers resistance to ampicillin or its isogenic counterpart as substrates were examined continuously over 13 d. Rate of production of SCFA was measured to determine functional changes in the rumen model and single-strand conformational polymorphism was used to detect alterations in structure of the microbial community. Rumen contents treated with ampicillin displayed a marked decrease in the rate of production of SCFA and diversity of the microbial community was reduced severely. In the presence of transgenic maize, however, the patterns of change of rumen micro-organisms and their metabolic profiles were different from that of rumen fluid incorporating maize bred conventionally. Recovery of propionate production was observed both in the rumen fluid fed transgenic and conventional maize after a delay of several days but recovery occurred earlier in fermenters fed transgenic maize. Alterations in the microbial population structures resulting from the ampicillin challenge were not reversed during the experimental run although there was evidence of adaptation of the microbial communities over time in the presence of the antibiotic, showing that populations with different microbial structures could resume a pre-challenge metabolic profile following the introduction of ampicillin, irrespective of the source of the plant material in the growth medium.

Ampicillin↗

PubMed2006

Detection of norovirus capsid protein in authentic standards and in stool extracts by matrix-assisted laser desorption ionization and nanospray mass spectrometry.

Mass spectrometry (MS) represents a rapid technique for the identification of microbial monocultures, and its adaptation to the detection of pathogens in real-world samples is a public health and homeland security priority. Norovirus, a leading cause of gastroenteritis in the world, is difficult to monitor because it cannot be cultured outside the human body. The detection of norovirus capsid protein was explored using three common MS-based methods: scanning of intact proteins, peptide mass fingerprinting, and peptide sequencing. Detection of intact target protein was limited by poor selectivity and sensitivity. Detection of up to 16 target peptides by peptide mass fingerprinting allowed for the reproducible and confident (P < 0.05) detection of the 56-kDa norovirus capsid protein in the range of 0.1 x 10(-12) to 50 x 10(-12) mol in authentic standards of recombinant norovirus virus-like particles (VLPs). To explore assay performance in complex matrixes, a non-gel-based, rapid method (2 to 3 h) for virus extraction from human stool was evaluated (72% +/- 12% recovery), and additional analyses were performed on norovirus-free stool extracts fortified with VLPs. Whereas peptide mass fingerprinting was rendered impractical by sample interferences, peptide sequencing using nanospray tandem MS facilitated unambiguous identification of > or =250 fmol of capsid protein in stool extracts. This is the first report on MS-based detection of norovirus, accomplished by using structurally identical, noninfective VLPs at clinically relevant concentrations. It represents an important milestone in the development of assays for surveillance of this category B bioterrorism agent.

Amino Acid Sequence↗

PubMed1999

Resistance responses of microorganisms in food environments.

Food borne microorganisms display a broad spectrum of resistance responses to naturally occurring and intentionally added antimicrobial agents. Resistance may be conferred by innate structural features of the bacterial strain such as an impermeable outer membrane or a mechanism for antibiotic-inactivation. Bacteria previously susceptible to an antimicrobial compound can acquire resistance through mutation or through genetic transfer processes such as transformation, transduction, and conjugation. Resistance can also be conferred by biofilm formation on food processing surfaces as an adaptive response to protect colonies from cleaning and sanitation. Resistant pathogens are a global problem, facilitated by international trade of raw and processed foods. Cross resistance between clinical and nonclinical antimicrobials can exist and is of concern. The development of resistant foodborne pathogens has been attributed to increased antibiotic use in hospitals, outpatient facilities, and veterinary applications. Resistant microorganisms can also develop as a result of physical processes used in food preservation, such as acid treatments and irradiation processes. Strategies to effectively counter resistance development include: changing current practices of antibiotic usage, developing new antibiotics, applying hurdle preservation approaches, preventing bacterial adhesion, and utilizing competitive exclusion. This paper presents an overview of problems arising from the development of microbial resistance, and explores possible solutions for detecting and defeating the adaptive changes of microorganisms.

Drug Resistance, Microbial↗

PubMed2004

Cryopreservation reduces the concentration of detectable bacteria in contaminated peripheral blood progenitor cell products.

BACKGROUND: Microbial contamination of PBPC products PBPCPs may cause severe clinical complications. There-fore, we investigated the influence of cryopreservation on the sensitivity to detect bacterial contaminations in PBPCPs. STUDY DESIGN AND METHODS: Expired PBPCPs (n = 29) were thawed, and defined concentrations of Staphylococcus epidermidis or Escherichia coli were inoculated into each bag. After 60 minutes of intermixing, a representative aliquot was drawn and cultured on Mueller-Hinton agar for 24 hours. Then, the products were cryopreserved for 24 hours, and the procedure was repeated as mentioned above. The total numbers of CFUs were counted before and after cryopreservation. RESULTS: A mean concentration of 2529 CFUs per mL of S. epidermidis was determined before cryopreservation versus 2182 CFUs per mL after cryopreservation, demonstrating a decrease of detectable colonies (p < 0.05). For E. coli, the mean numbers were 424 CFUs per mL before cryopreservation and 343 CFUs per mL after cryopreservation, also showing a decrease (p < 0.05). CONCLUSION: The cryopreservation reduces the concentration of detectable bacteria in contaminated PBPCPs. Especially in sterility testing of PBPCPs with low bacterial contamination, this phenomenon could lead to false-negative results with severe clinical consequences.

Bacteria↗

PubMed1978

Microbial-like antigens in human leukemia.

Antigens present in leukemic sera and organ extracts, but absent from non-leukemic sera and tissues, were detected by examining their reactions with anti-microbial antisera by means of counter-immunoelectrophoresis. Out of 110 different antisera used, 12 antisera, those produced against Micropolyspora, Coccidioides, Salmonella, Mycoplasma, Mycobacterium simiae, Absidia, pseudorabies virus and adenovirus, proved to react regularly with the leukemic sera. Absorption studies point to an immunological specificity of these cross-antigenicities. Interpretations and implications of these discoveries are discussed in the paper.

Antigens, Bacterial↗

PubMed2004

Liquid chromatography-mass spectrometry analysis of hydroxylated polycyclic aromatic hydrocarbons, formed in a simulator of the human gastrointestinal tract.

Described is a liquid chromatography-mass spectrometry (LC-MS) procedure for the determination of hydroxylated biotransformation products of polycyclic aromatic hydrocarbons (PAH) in the human gastrointestinal tract. The formation of hydroxylated PAHs was monitored upon incubation of PAHs with colon microbiota from the Simulator of the Human Intestinal Microbial Ecosystem (SHIME). The analytical method consisted of a biomass removal step followed by a solid phase extraction (SPE) step using C18 packed columns to remove non-digested food compounds and microbial metabolites that interfere with the detection of the target compounds. For quantification, 9-hydroxyphenanthrene (13)C(6)was used as the internal standard. The detection limits of the hydroxylated PAHs were generally in the range 0.36-14.09 microg x l(-1), based on a signal/noise ratio of 3:1. The recovery of hydroxylated PAHs in intestinal suspension was variable ranging from 45 to 107%, with relative standard deviation (R.S.D.) between 5 and 17%. The analytical procedure was used to show the microbial production of 1-hydroxypyrene and 7-hydroxybenzo(a)pyrene, metabolites that may give colon incubated PAHs bioactive properties.

Calibration↗

PubMedDate not supplied

[Detection of bacterial molecular markers in the tissue of cardiac valves in normal and pathological states by gas chromatography and mass spectrometry].

Samples from cardiac valves of 31 patients were analyzed by gas chromatography and mass spectrometry. The algorithm of mass spectrometric parameters was developed, which permitted the determination of about 200 known microbial fatty acids, aldehydes and sterols, sufficient for the detection and quantitative determination of more that 170 taxons of clinically significant microorganisms on the genus or species levels. The quantitative and qualitative differences in the composition of microbial markers of endocardial valves in normal and pathological states, particularly in cases of infectious endocarditis, were detected. The participation of 37 microbial taxons in the process was confirmed. The level of endocardium colonization in infectious endocarditis reached from 2 to 7 x 10(9) microbial cells/g of valvular tissue (which exceeded twofold the equivalent concentrations of the marker in the normal state). In terms of quantity, the leading role was played by Cardiobacterium hominis.

Adolescent↗

PubMed2004

Sulfate-reducing bacteria-dominated biofilms that precipitate ZnS in a subsurface circumneutral-pH mine drainage system.

The microbial diversity of ZnS-forming biofilms in 8 degrees C, circumneutral-pH groundwater in tunnels within the abandoned Piquette Zn, Pb mine (Tennyson, Wisconsin, USA) has been investigated by molecular methods, fluorescence in situ hybridization (FISH), and cultivation techniques. These biofilms are growing on old mine timbers that generate locally anaerobic zones within the mine drainage system. Sulfate-reducing bacteria (SRB) exclusively of the family Desulfobacteriaceae comprise a significant fraction of the active microbiota. Desulfosporosinus strains were isolated, but could not be detected by molecular methods. Other important microbial clusters belonged to the beta-, gamma-, and epsilon-Proteobacteria, the Cytophaga/Flexibacter/Bacteroides-group (CFB), Planctomycetales, Spirochaetales, Clostridia, and green nonsulfur bacteria. Our investigations indicated a growth dependence of SRB on fermentative, cellulolytic, and organic acid-producing Clostridia. A few clones related to sulfur-oxidizing bacteria were detected, suggesting a sulfur cycle related to redox gradients within the biofilm. Sulfur oxidation prevents sulfide accumulation that would lead to precipitation of other sulfide phases. FISH analyses indicated that Desulfobacteriaceae populations were not early colonizers in freshly grown and ZnS-poor biofilms, whereas they were abundant in older, naturally established, and ZnS-rich biofilms. Gram-negative SRB have been detected in situ over a period of 6 months, supporting the important role of these organisms in selective ZnS precipitation in Tennyson mine. Results demonstrate the complex nature of biofilms responsible for in situ bioremediation of toxic metals in a subsurface mine drainage system.

Bacteria↗

PubMed1992

[Evaluation of biological toxicity of livestock fecal deordoring microbial agents].

Eight commercial livestock microbial agents were selected for the evaluation of biological toxicity. The general physical, chemical and microbial analyses of these microbial agents were performed and the acute toxicity of mice, aquatic living organisms and the germinated inhibition of vegetable seeds by these microbial agents were also estimated for the evaluation of biological toxicity. The results have shown that all livestock microbial agents have no pathogenic Salmonella and Staphylococcus aureus been detected. However, the acute biological toxicity test of water extractant of these microbial agents indicated that microbial agent A, B, C, D and M appeared various toxicity to the mice. The dosage of LC50 (48 hr) to the mice was 3 mg/ml for microbial agent A (150 mg/kg mouse, high toxicity), 90 mg/ml for microbial agent B (4.5 g/kg mouse, low-medium toxicity), 92 mg/ml for microbial agent C (4.6 g/kg mouse, low-medium toxicity), 118 mg/ml for microbial agent D (5.9 g/kg mouse, low toxicity) and nontoxicity for microbial agent M, respectively. In addition, the dosage of LC50 to aquatic organisms Daphina similis and Lemna minor, was < 0.01 mg/ml and 0.13 mg/ml for microbial agent A, 1.73 mg/ml and 10 mg/ml for microbial B, 3 mg/ml and > 20 mg/ml for microbial C, 0.56 mg/ml and 14 mg/ml for microbial agent D, respectively. All microbial agents also show various inhibitory effects to the seed germination and root extension of vegetable crops. The study has demonstrated that the biological toxicity of livestock microbial agents was following such order: microbial A > B, C > D > M. The animal has shown more sensitive than plant to the microbial agents.

Animals↗

PubMed2004

A survey of indigenous microbial hydrocarbon degradation genes in soils from Antarctica and Brazil.

Total community DNA from 29 noncontaminated soils and soils impacted by petroleum hydrocarbons and chloro-organics from Antarctica and Brazil were screened for the presence of nine catabolic genes, encoding alkane monooxygenase or aromatic dioxygenases, from known bacterial biodegradation pathways. Specific primers and probes targeting alkane monooxygenase genes were derived from Pseudomonas putida ATCC 29347 (Pp alkB), Rhodococcus sp. strain Q15 (Rh alkB1, Rh alkB2), and Acinetobacter sp. ADP-1 (Ac alkM). In addition, primers and probes detecting aromatic dioxygenase genes were derived from P. putida ATCC 17484 (ndoB), P. putida F1 (todC1), P. putida ATCC 33015 (xylE and cat23), and P. pseudoalcaligenes KF707 (bphA). The primers and probes were used to analyze total community DNA extracts by using PCR and hybridization analysis. All the catabolic genes, except the Ac alkM, were detected in contaminated and control soils from both geographic regions, with a higher frequency in the Antarctic soils. The alkane monooxygenase genes, Rh alkB1 and Rh alkB2, were the most frequently detected alk genes in both regions, while Pp alkB was not detected in Brazil soils. Genes encoding the aromatic dioxygenases toluene dioxygenase (todC1) and biphenyl dioxygenase (bphA) were the most frequently detected in Antarctica, and todC1 and catechol-2,3-dioxygenase (cat23) were the most frequent in Brazil soils. Hybridization analysis confirmed the PCR results, indicating that the probes used had a high degree of homology to the genes detected in the soil extracts and were effective in detecting biodegradative potential in the indigenous microbial population.

Acinetobacter↗

PubMed2006

Conventional and real-time polymerase chain reaction assessment of the fate of transgenic DNA in sheep fed Roundup Ready rapeseed meal.

Conventional and real-time PCR were used to detect transgenic DNA in digesta, faeces and blood collected from six ruminally and duodenally cannulated sheep fed forage-based (F) or concentrate-based (C) diets containing 15% Roundup Ready (RR) rapeseed meal (n 3). The sheep were adapted for 14 d to F or C diets containing non-GM rapeseed, then fed the RR diets for 11 d. On day 12, they were switched back to non-GM diets for a further 11 d. Ruminal and duodenal fluids (RF, DF) and faecal samples were collected at 3 or 4 h intervals over the 4 d immediately following the last feeding of GM diets. DNA was isolated from whole RF and DF, from the cell-free supernatant fraction, and from culture fermentation liquid. Blood was collected on days 1, 5 and 9 of feeding the RR rapeseed meal. The 1363 bp 5-enolpyruvylshikimate-3-phosphate synthase transgene (epsps) was quantifiable in whole RF and DF for up to 13 h, and a 108 bp epsps fragment for up to 29 h. Transgenic DNA was not detectable in faeces or blood, or in microbial DNA. Diet type (F v. C) did not affect (P>0.05) the quantity of transgenic DNA in digesta. More (P<0.05) transgenic DNA was detected in RF than in DF, but there was an interaction (P<0.05) between sample type and collection time. In supernatant fractions from RF and DF, three different fragments of transgenic DNA ranging in size from 62 to 420 bp were not amplifiable.

Animal Feed↗

PubMed2026

Resistant starch types 2 and 4 induce distinct and reversible changes in the human gut microbiome.

Resistant starch (RS) can confer benefits for the gut microbiome and host cardiometabolic health. However, different types of resistant starch can differentially affect gut microbiome composition and functional capacity, especially given interindividual variability in responses, thus limiting the application of resistant starch in dietary strategies. We used shotgun metagenomics to perform a secondary analysis of samples collected during a previously reported randomized clinical trial to determine the effects of dietary supplementation with two types of resistant starch (RS2 and RS4) and a digestible starch (control) on the gut microbiome. Both resistant starch types induced distinct but transient alterations in the gut microbial community. RS2 enriched the keystone degrader, Ruminococcus bromii, and Blautia glucerasea, whereas RS4 favored Parabacteroides distasonis and known but uncharacterized microbial species such as a Lachnospiraceae bacterium. Moreover, we detected strain-level differences in the response of Bifidobacterium adolescentis to resistant starch. Microbial functional profiling revealed an enhanced capacity for complex carbohydrate utilization following resistant starch intake, including increased abundance of specific α-amylases, glycoside hydrolases, starch utilization systems, and other currently uncharacterized genes. Identifying the bacterial strains and genes that respond to different RS types will help to more accurately predict who will benefit from a given RS type. Our findings demonstrate that RS2 and RS4 differentially shape microbial ecology and metabolic capacity and provide a foundation for microbiome-informed personalization of resistant starch-based dietary interventions.IMPORTANCEDietary intake influences human health by modulating metabolism, partly by shaping the microbiota inhabiting the gut. Resistant starch (RS), a dietary fiber, is associated with metabolic improvements. While previous research has explored how RS alters the gut microbiome, RS comprises five types with differing physical and chemical characteristics, and the distinct impacts of each type on the microbiome and host health have not been fully characterized, particularly using high-resolution approaches such as shotgun metagenomics. In this secondary analysis of samples from a longitudinal crossover intervention study, we link dietary supplementation with RS2 and RS4 with distinct and transient changes in the composition and functional potential of the human gut microbiome. Specifically, we identify species that increase in abundance with each RS type, accompanied by increases in genes and pathways involved in complex carbohydrate utilization. The findings support the development of precision nutrition strategies utilizing RS supplementation to improve metabolic health.This study is registered with ClinicalTrials.gov as NCT05743790.

Humans↗