Alliin alters gut microbiota and gene expression of colonic epithelial tissues

Abstract

Alliin is a natural organosulfur‐containing phytochemical in garlic. It is possible that alliin can regulate the gut microbiota for its strong antimicrobial activity against many pathogens. Here, we assessed whether alliin impacts the distal small intestinal bacteria, hence the cecal microbiota, thus altering the gene expression of colonic epithelial tissues (CETs). Eighty mg/kg alliin was orally administered to rats for 14 days, and the 16S rDNA from small intestinal and cecal microbiota as well as mRNA from CETs were sequenced and analyzed. The results showed that alliin consumption affected microbiota composition in both the small intestine and cecum, although there was only one specific genus, Allobaculum that was significantly altered in the rat cecum. The altered composition of microbiota indirectly impacted 174 genes in the CETs. Specifically, five genes, including RT1‐Ba, RT1‐Bb, Cd80, Madcam1, and Aicda, indicated this consumption related to the intestinal immune network for IgA production. Practical applications We firstly reported alliin consumption in vivo potentially affected the intestinal immunity of healthy rats by slightly alteration of microbiota composition in small intestine and cecum. The alteration subsequently amplified, resulting in the change of the colonic epithelial expression of several genes related to the intestinal immune network for IgA production. Hence, we suggested the alliin consumption may potentially affect the immune system of healthy individuals by alteration of gut microbiota and epithelial gene expression.

Beneficial Effects of Organosulfur Compounds from Allium cepa on Gut Health: A Systematic Review

“…Similar findings were obtained in another study conducted with alliin in healthy rats [68]. The group that took alliin presented a higher abundance of Firmicutes and a lower abundance of Bacteroidetes than the control group, although the differences were not statistically significant [68].…”

“…Beyond Ruminococcaceae, mice fed with supplemented diet experienced an increase in other classes of Firmicutes and also Actinobacteria, along with a reduction in the number of Bacteroidetes and Proteobacteria, though these results did not reach a significant level [66]. Similar findings were obtained in another study conducted with alliin in healthy rats [68]. The group that took alliin presented a higher abundance of Firmicutes and a lower abundance of Bacteroidetes than the control group, although the differences were not statistically significant [68].…”

“…Two extra articles not identified by the electronic databases were added as the authors were aware of their existence. Finally, as shown in Figure 3, a total of 17 articles [62][63][64][65][66][67][68][69][70][71][72][73][74][75][76][77][78] were found to be eligible for the present systematic review following the full-text eligibility assessment. The characteristics of the selected articles are summarized in Table 1.…”

“…Vezza et al [67] investigated the effects of one onion-derived OSC in two models with mice with colitis, which were able to modulate the GM composition of the treated mice. Two articles studied how the consumption of an OSC derived from garlic (alliin) influenced the GM in healthy rats [68], as well as in mice with obesity induced by a high-fat diet (HFD) [66]. The results showed that, in both cases, the gut health of the treated animals improved following changes in their GM populations.…”

Flaxseed Polysaccharide Alters Colonic Gene Expression of Lipid Metabolism and Energy Metabolism in Obese Rats

“…These processes were performed as described previously [15]. Briefly, total RNA of the colonic epithelial tissues was extracted using TRIzol reagent.…”