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Differential effects of non-absorbable carbohydrates and food fibers on themicrobiota hydrogen and methane production in low- and high-methane-producing ratsтезисы доклада
- Авторы: Anastasiya Ivanova, Obolenskaya Olga, Shirokov Ivan, Toshchakov Stepan, TatianaKuropatkina, Belousova Margarita, Medvedev Oleg
- Сборник: FFC's 39;s 31st International Conference
- Тезисы
- Год издания: 2023
- Аннотация: Background: Non-absorbable carbohydrate (lactulose) and food fibers are used for feeding gut microbiota, producing biomarkers with positive effects on health: generation of molecular hydrogen with antioxidant activity, short-chain fatty acids for keeping intestine-blood barrier, and stimulation of immunity. It is shown that different food fibers induce different responses of microbiota that depend on the taxonomical composition of the microbiota microorganisms. Clinical and experimental studies have shown that 40-50% of humans and laboratory animals generate just hydrogen, whereas the rest of them produce both, hydrogen (H2) and methane (CH4), the latter is exclusively produced by the methanogenic Archaea (Pimentel et al., 2020; Modesto et al., 2022). The percentage of methane-produces increases with age. The potential contribution of methanogenic Archaea in the specific effects of different carbohydrates on the gut microbiota remains unknown. Objective: To evaluate the potential effect of methanogenic Archaea on the biomarkers of the microbiota fermentation function was the aim of our study. Methods: We have discovered that Wistar rats from two nurseries in the Moscow district are the different concerning generation of methane by the microbiota. Rats from the Puschino nursery predominantly produced hydrogen (M- group, n=25), whereas rats from the Stolbovaya nursery produced a lot of methane (M+group, n=25). So, we used rats from these two nurseries as models of similar groups of humans. Before the breath test, the rats were deprived of food for approximately 12 hours. Three types of dietary compounds were chosen as a carbohydrate load: lactulose (2.0 g/kg), partially hydrolyzed guar gum (PHGG), (Optifiber®) (4.0 g/kg), and inulin (4.0 g/kg). A breath test with each carbohydrate was performed in sequence on the rats of both groups every other day. H2 and CH4 levels produced by the microbiota were measured in air samples by gas chromatograph (TRILyzer mBA-3000, Japan). Microbial community analysis in the feces of both groups was performed using high-throughput 16S V4 amplicon sequencing. Results: Gavage of the tested carbohydrates followed by the increase of H2 in exhaled air in the "M-group" of rats, the maximum response was to the administration of lactulose and minimal – to inulin. Responses to the used carbohydrates differed significantly, PHGG vs Inulin (p=0.03), Lactulose vs PHGG (p=0.009), and Lactulose vs Inulin (p<0.0001). At the same time, when using all dietary fibers, no significant increase in the level of methane relative to the "fasting" state (zero measurement point) was recorded. In the "M+ group" we did not observe significant changes in H2 response, but it was a high increase in the level of methane. Detailed analysis of the microbial communities in the groups "M-" and "M+" have shown much higher Alpha and Beta diversities in "M+" group (p <0.001). In both groups of rats, representatives of the phyla Bacteriodota and Firmicutes make up the majority of the microbiome. The correlations between the levels of H2 and CH4 in the exhaled air and the quantitative content of various microorganisms of both groups were observed, as well. Conclusion: Two groups of rats used in our study imitate groups of humans producing mainly hydrogen or methane. It was shown that in the group of methane-producing rats, it was impossible to increase levels of H2 in response to any type of usually used carbohydrates. We assume that the data received could be explained by the high activity/quantity of CH4-producing microorganisms that can consume any amount of H2- produced. We recommend screening humans with non-invasive H2/CH4 breath tests to offer personalized advice on the healthy consumption of food fibers.
- Добавил в систему: Медведев Олег Стефанович