Gut Bacteria Use Hydrogen to Better Digest Fiber in Obese Pigs
- Authors
- Xuan Li, Chunlong Mu, Haiqin Wu, Erwin G. Zoetendal, Ruihua Huang, Kaifan Yu, Weiyun Zhu
- Journal
- ISME Communications
- Year
- 2025
- DOI
- 10.1093/ismeco/ycaf043
- Study Type
- Pig
- Outcome
- Positive
- Peer Reviewed
- Yes
- Country
- China
- Health Condition
- Digestive Disorders
- Body System
- Digestive
TL;DR
Obese-type Meishan pigs are better at breaking down dietary fiber than lean-type Yorkshire pigs, thanks to their gut bacteria that produce more beneficial fatty acids and use hydrogen more efficiently.
Key Finding
Obese-breed pigs digest dietary fiber more effectively than lean-breed pigs because they harbor more hydrogen-consuming microbes that prevent hydrogen buildup, allowing fiber-degrading bacteria to work more efficiently and produce more short-chain fatty acids.
Summary
This study compared how two pig breeds—one naturally obese and one lean—digest dietary fiber differently. Researchers found that obese-breed pigs had more bacteria in their gut that break down fiber, and these bacteria were better at converting fiber into short-chain fatty acids (beneficial compounds produced during digestion). The key difference was that obese-breed pigs had more hydrogen-consuming microbes that help remove excess hydrogen, which allows fiber-digesting bacteria to work more efficiently.
Practical Takeaway
While this research is in pigs and does not directly test hydrogen water, it suggests that microbial hydrogen metabolism may play a role in how efficiently the gut breaks down fiber. The study does not involve hydrogen water consumption and cannot be applied to human health claims without further research in humans.
Abstract
Dietary fiber is widely recognized for its benefits to human health. Individual variations in the ability to degrade dietary fiber are influenced by the gut microbiome that may be associated with the host's metabolic phenotype and genetic diversity. This is exemplified by the distinct fiber digestibility observed in obese (e.g. Meishan) and lean-breed (e.g. Yorkshire) pigs. However, the underlying mechanisms remain unclear. The present study found that with the same diet under the same environment, the obese-type Meishan pigs showed greater dietary fiber digestibility and harbored higher abundances of polysaccharide-degrading bacteria (Bacteroides, Treponema, and Paraprevotella) compared to lean-type Yorkshire pigs. Metatranscriptomic profiling revealed that the elevated presence of Bacteroides contributed to the enrichment of carbohydrate-active enzymes, particularly those degrading arabinoxylan, indicating a preference for arabinoxylan as a substrate in Meishan pigs. Further enzymatic-product measurements, combined with microbial enzyme profiles, validated greater microbial conversion of xylose into short-chain fatty acids (SCFAs) in Meishan pigs. Additionally, higher abundances of hydrogenotrophic microbes (Methanobrevibacter and Blautia) were detected in the Meishan gut, along with the enrichment of methanogenesis and acetogenesis pathways. To determine whether methanogenesis drives inter-breed variation in arabinoxylan degradation, an in vitro experiment using the methanogen inhibitor, 2-bromoethanesulfonate (BES) was performed. The results confirmed that Meishan gut microbiome effectively reduced hydrogen accumulation through methanogenesis, promoting arabinoxylan degradation. Conversely, inhibiting methanogenesis by BES led to hydrogen accumulation, reduced SCFAs, β-xylosidase activity, and Bacteroides abundances. These findings demonstrate that the Meishan pigs have a superior ability of dietary fiber utilization with greater microbial conversion to more SCFAs, which is linked to stronger hydrogenotrophic methanogenesis. This study reinforces the role of gut microbial hydrogenotrophy in dietary fiber utilization in pigs.