Improvement of human faecal flora-associated mouse model for evaluation of the functional foods

Abstract

Aims: Animal models are required for evaluation of the functional foods such as pro/prebiotics exerting effects through the metabolism of the intestinal microflora. The object of this study was to establish new human floraassociated mice reflecting the environment of the human intestinal tract. Methods and Results: We inoculated a human faecal suspension into segmented filamentous bacteria (SFB) monoassociated mice as a model system. In both human flora (HF) and SFB-associated mouse (HF-SFB mouse), intestinal characteristics such as the composition of intraepithelial lymphocytes, the expression of major histocompatibility complex (MHC) class II molecules and the number of immunoglobulin A-producing cells in the mucosa was closer to those of conventionally reared mice than was case with human flora-associated mice (HF mice) lacking SFB. Several predominant bacterial groups except lactobacilli in human flora were found in faeces of HF-SFB mice. Lactobacilli established small populations in the gut of HF-SFB mice when administered before inoculation with the human flora. Faecal enzymatic activities and organic acid concentration of HF-SFB mice proportionally reflected those of the donor subject. Conclusion: We established a new human flora-associated mouse (HF-SFB mouse), in which intestinal characteristics are normally developed and their major microbial composition reflect the human. Significance and Impact of the Study: HF-SFB mice are a valuable model for studying pro/prebiotic effects on the human intestine.

Movement and Fixation of Intestinal Microbiota after Administration of Human Feces to Germfree Mice

“…HFA mice have been exploited and used as a tool reflecting human intestinal microbial ecology (6,7,30). Although the development of intestinal microbiota in HFA mice has been revealed by culture methods (12), there are few reports of the use of molecular methods (5,7,15). Our work has revealed the movement and persistence of human intestinal microbiota in formerly germfree mice by T-RFLP analysis.…”

“…These limitations include differences in enzyme activity, concentrations of putrefactive products, and immunological activation by the composition of fecal bacteria (13,15). Previous studies reported that 60% to 80% of the observable bacteria in human intestines could not be cultivated (10,37).…”

“…These limitations may therefore be caused by composition differences in microbiota of intestinal contents between humans and HFA mice. However, there are few reports about the use of molecular techniques with HFA mice or rats to determine the composition of microbiota including unidentified bacteria (5,7,15).…”

Inter-species transplantation of gut microbiota from human to pigs

“…Such HFA animal model has significantly facilitated progress in researches of human gut ecology, metabolism and immunity (Hazenberg et al, 1981;Roland et al, 1996;Oozeer et al, 2002;Gerard et al, 2004;Wilcks et al, 2004). However, owing to the significant differences in basic anatomy and physiology of rodents to human, key members of human gut microbiota such as bifidobacteria do not colonize the rodent gut; and rodents do not develop a full repertoire of immune responses unless some rodent-specific gut bacteria are reintroduced back into the gut (Raibaud et al, 1980;Imaoka et al, 2004). Thus, results obtained from these mice/rat models often have low relevance to human beings.…”

Rose Hip and Lactobacillus plantarum DSM 9843 Reduce Ischemia/Reperfusion Injury in the Mouse Colon

“…The results obtained from experiments on conventional animals may not be applicable to the human gut ecosystem, because the microflora of these animals differs in composition from that of humans (34). The lactobacilli is a major group in the intestinal microbiota of mice (35), which is not the case in humans where lactobacilli regularly are present but in a smaller proportion of the microflora (36,37).…”