2025 - Sustainable Industrial Processing Summit
SIPS2025 Volume 7. Tanner Intl. Symp. / Pharmaceutical Sciences and Biotechnology
| Editors: | F. Kongoli, S. Buchmann, M. Bultmann, I. Karim, G. Kimura, G. Knipp, H. Leuenberger, M. Makanga, N. Menshutina, P. Swaan, H. Tarabishi |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2025 |
| Pages: | 177 pages |
| ISBN: | 978-1-998384-50-1 (CD) |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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FUNCTIONAL IMPACT OF SHORT-TERM FASTING ON HUMAN GUT MICROBIOTA AND SECONDARY BILE ACID METABOLISM
Syeda Anchel Zahra1;1CHARITE UNIVERSITY OF MEDICINE, Berlin, Germany;
Type of Paper: Regular
Id Paper: 168
Topic: 80
Abstract:
Bile acids are increasingly recognized as critical mediators of host-microbiome interactions, influencing a wide range of physiological processes including glucose and lipid metabolism, inflammation, and cardiovascular function. Beyond their classical role in dietary fat emulsification, bile acids act as signaling molecules through receptors such as FXR and TGR5, linking gut microbial activity to systemic health. While the microbial conversion of primary to secondary bile acids—primarily via bile salt hydrolase (BSH) and 7α-dehydroxylase pathways—is well established, the dynamic responsiveness of this system to acute dietary changes, particularly fasting, remains incompletely understood.
In this study, we investigated how a five-day 250 kcal vegetable juice-only fasting intervention affects gut microbiota composition and secondary bile acid metabolism in humans. Thirty-six healthy adults underwent supervised fasting, with fecal and plasma samples collected immediately before and after the intervention. To assess shifts in key microbial taxa associated with bile acid metabolism and gut barrier integrity, we performed quantitative PCR (qPCR) targeting Akkermansia muciniphila, Bacteroides ovatus, Bacteroides fragilis, and Prevotella copri. These taxa were selected based on their known involvement in mucin degradation, bile acid modification, and metabolic disease associations. However, qPCR analysis revealed no statistically significant changes in their relative abundance following fasting. Despite the absence of significant taxonomic shifts, previous studies suggest that microbial functions can adapt independently of community structure. To explore this further, shotgun metagenomic sequencing is currently underway to identify potential changes in the functional capacity of the microbiome, particularly in genes involved in bile acid metabolism such as the bile acid-inducible (bai) operon and BSH-related pathways. These preliminary findings highlight the complexity and potential disconnect between microbial composition and function, emphasizing the importance of multi-omic approaches in microbiome research. Functional changes in bile acid metabolism during short-term fasting may have important implications for metabolic flexibility and gut-liver axis signaling, even in the absence of major taxonomic shifts. Ultimately, this work contributes to a more nuanced understanding of how acute nutritional interventions influence host-microbiome dynamics and opens new avenues for targeting bile acid pathways in the context of metabolic and cardiovascular health.