In vitro Effects of Cellulose Acetate on Fermentation Profiles, the Microbiome, and Gamma-aminobutyric Acid Production in Human Stool Cultures.

Gamma-aminobutyric acid (GABA) is considered as a potential candidate substance that mediates the effects of intestinal bacteria on human mental health. In the present study, we evaluated the effect of water-soluble cellulose acetate (WSCA), a type of cellulose ester, on fermentation and microbial profiles, and GABA production in human stool cultures prepared from fresh feces from volunteers. In addition, the GABA-producing ability of Bacteroides uniformis, which can utilize WSCA, was evaluated in a pure-culture study. All incubations were conducted anaerobically. WSCA supplementation increased (P < 0.05) acetate and propionate production and decreased (P < 0.05) the pH in human fecal cultures. WSCA significantly altered the microbiota, selectively increasing the relative abundance of B. uniformis (P < 0.05). Pure-culture study results revealed that B. uniformis produces GABA, possibly via a glutamate-dependent acid resistance system under low pH conditions. In conclusion, WSCA could be a potential prebiotic material that is fermented by intestinal bacteria and increases short-chain fatty acid and GABA production in the human gut. Bacteroides uniformis might play an important role in both WSCA degradation and GABA production in the intestine.

Evaluation of post-colostrum ingestion changes in the protein composition of peripheral blood of newborn piglets: A pilot study.

Putatively, colostral proteins are partly absorbed and transferred to blood circulation in newborn piglets, which suggests that colostrum ingestion alters the protein composition of their blood. Here, we conducted a pilot study to estimate the changes in the protein composition of piglet blood. Plasma collected from piglets pre- and post-ingestion of colostrum (PreC and PostC) was analyzed by shotgun proteomics. Proteins in colostrum were also analyzed. We identified 393 and 427 proteins in PreC and PostC plasma, respectively, and 596 colostral proteins. Whereas 202 unique proteins were identified in PostC, PreC and PostC commonly shared 225 proteins. By contrast, when compared with PreC, 54 proteins in PostC had their emPAI values increased >2-fold. Notably, using plasma samples collected from a separate experiment, the concentrations of growth differentiation factor 8 and haptoglobin were higher in PostC than in PreC, which was validated by ELISA. Approximately 60% of the uniquely identified or highly concentrated proteins in PostC were also found in colostrum, which were likely, at least partly, transferred from colostrum. The present study demonstrated that the protein composition of plasma of newborn piglets drastically changed post-colostrum ingestion, partly due to transfer of colostral proteins.

Effect of trehalose supplementation in milk replacer on the incidence of diarrhea and fecal microbiota in preweaned calves.

Trehalose, a nonreducing disaccharide consisting of d-glucose with α,α-1,1 linkage, was evaluated as a functional material to improve the gut environment in preweaned calves. In experiment 1, 173 calves were divided into two groups; the trehalose group was fed trehalose at 30 g/animal/d with milk replacer during the suckling period, and the control group was fed nonsupplemented milk replacer. Medication frequency was lower in the trehalose group (P < 0.05). In experiment 2, calves (n = 20) were divided into two groups (control group [n = 10] and trehalose group [n = 10]) based on their body weight and reared under the same feeding regimens as in experiment 1. Fresh feces were collected from individual animals at the beginning of the trial (average age 11 d), 3 wk after trehalose feeding (experimental day 22), and 1 d before weaning, and the fecal score was recorded daily. Fecal samples were analyzed for fermentation parameters and microbiota. The fecal score was significantly lower in the trehalose group than in the control group in the early stage (at an age of 14 to 18 d; P < 0.05) of the suckling period. Calves fed trehalose tended to have a higher proportion of fecal butyrate on day 22 than calves in the control group (P = 0.08). Population sizes of Clostridium spp. were significantly lower (P = 0.036), whereas those of Dialister spp. and Eubacterium spp. tended to be higher in the feces of calves in the trehalose group on day 22 (P = 0.060 and P = 0.083). These observations indicate that trehalose feeding modulated the gut environment and partially contributed to the reduction in medication frequency observed in experiment 1.