Metatranscriptomic analysis of colonic microbiota’s functional response to different dietary fibers in growing pigs

Abstract

Background Dietary fibers are widely considered to be beneficial to health as they produce nutrients through gut microbial fermentation while facilitating weight management and boosting gut health. To date, the gene expression profiles of the carbohydrate active enzymes (CAZymes) that respond to different types of fibers (raw potato starch, RPS; inulin, INU; pectin, PEC) in the gut microbes of pigs are not well understood. Therefore, we investigated the functional response of colonic microbiota to different dietary fibers in pigs through metatranscriptomic analysis. Results The results showed that the microbial composition and CAZyme structure of the three experimental groups changed significantly compared with the control group (CON). Based on a comparative analysis with the control diet, RPS increased the abundance of Parabacteroides, Ruminococcus, Faecalibacterium and Alloprevotella but decreased Sutterella; INU increased the relative abundance of Fusobacterium and Rhodococcus but decreased Bacillus; and PEC increased the relative abundance of the Streptococcus and Bacteroidetes groups but decreased Clostridium, Clostridioides, Intestinibacter, Gemmiger, Muribaculum and Vibrio. The gene expression of CAZymes GH8, GH14, GH24, GH38, GT14, GT31, GT77 and GT91 downregulated but that of GH77, GH97, GT3, GT10 and GT27 upregulated in the RPS diet group; the gene expression of AA4, AA7, GH14, GH15, GH24, GH26, GH27, GH38, GH101, GT26, GT27 and GT38 downregulated in the INU group; and the gene expression of PL4, AA1, GT32, GH18, GH37, GH101 and GH112 downregulated but that of CE14, AA3, AA12, GH5, GH102 and GH103 upregulated in the PEC group. Compared with the RPS and INU groups, the composition of colonic microbiota in the PEC group exhibited more diverse changes with the variation of CAZymes and Streptococcus as the main contributor to CBM61, which greatly promoted the digestion of pectin. Conclusion The results of this exploratory study provided a comprehensive overview of the effects of different fibers on nutrient digestibility, gut microbiota and CAZymes in pig colon, which will furnish new insights into the impacts of the use of dietary fibers on animal and human health.

Intake of slow-digesting carbohydrates is related to changes in the microbiome and its functional pathways in growing rats with obesity induced by diet

“…On the contrary, the OBE-ISR group revealed a decrease in the relative abundances of the genera Muribaculum, Blautia, and Ruminiclostridium 9. The results of a recent metatranscriptomic analysis of colonic microbiota are consistent with our findings; dietary fibers rich in inulin, among others, decreased Muribaculum genus in growing pigs (65), providing new insight into the effects of dietary fibers on animal health. There is, however, evident that the genus Blautia is more common in diets high in soluble fibers, which are beneficial to glucan fermentation, compared with rats fed dietary fiber derived from barley malts, brewer's spent grain, or barley extracts (containing significant amounts of β-glucan, soluble arabinoxylan, and insoluble arabinoxylan) (66).…”

Reduction of Redox Potential Exerts a Key Role in Modulating Gut Microbial Taxa and Function by Dietary Supplementation of Pectin in a Pig Model

“…The anaerobic condition in hindgut promotes the production of fermentation products. Prior studies have assessed the impact of pectin ingestion on the microbial community ( 5 to 7 ). However, there is little systemic knowledge about how pectin regulates gut microbiota.…”

Resistant Potato Starch Alters the Cecal Microbiome and Gene Expression in Mice Fed a Western Diet Based on NHANES Data

“…Not all members of one RS type have the same biological effects due to differences in their fine structure that may favor certain bacteria strains over others ( 16 , 17 ). RS2 has been shown to alter the microbiome in rodents ( 4 , 6 , 18 ), pigs ( 19 – 22 ), and humans ( 13 , 23 – 25 ).…”