It has been known that human gut microbiota modulates host health and the composition is affected by lifestyle, including the availability of dietary fiber. Tempeh, a kind of traditional fermented food from Indonesia, is rich in soluble fibers and microbial consortia. A previous study showed that tempeh could enhance IgA production and modulate gut microbiota composition in rats. Meanwhile, in human, tempeh supplementation for 16 days has increased the number of Akkermansia muciniphila significantly. Many Indonesians consume tempeh on a daily basis, but the effect of tempeh consumption for a longer period of time in human remains to be investigated. Therefore, the objective of this study was to investigate the effect of tempeh consumption in human for longer term, especially its effect in modulating gut microbiota composition. A total of sixteen (16) healthy females participated in this study. For the first 7 days, they were not allowed to consume any soy product; followed by 28 days of 100 gram of tempeh (n=10), or 200 mL of soymilk (n=6) consumption. Analysis of gut microbiota showed that soymilk and tempeh supplementation generated different profiles. Twenty-eight days of tempeh supplementation seemed to improve metabolic health markers better than soymilk treatment; significantly enhancing the presence of Bifidobacterium and A. muciniphila populations compared to those at the beginning of the study.

The usage of aspartame, as one of the most widely used sweetener, has been approved in many types of food products. Moreover, many studies have proven that replacing sugar with aspartame would contribute favorable effects on several health parameters; such as, body weight, blood glucose level, and inflammatory status. In this experiment, we examined the effects of aspartame consumption on some biomarkers; which potentially acted as early signals for a personal metabolic status. This study was aimed to investigate the effect of aspartame on the expression of a number of molecular markers related with appetite regulation (fto), fat accumulation markers (fabp4 and alt2) and inflammation marker (tnf-α) in Sprague Dawley rats. The population of Clostridium coccoides was also observed to give an insight about the effect of sweetener consumption on gut microbiota profiles. 15 healthy, male, eight-weeks old Sprague-Dawley rats were fed a standard diet and divided into 3 groups (n=5 for each): water only, sucrose (30% b/v), and aspartame (0.15% b/v). Body weight was measured weekly and blood glucose measurement was carried out on day 1 and 40. At the end of the experiment, all rats were euthanized and blood was collected from the vein. The liver, brain, and visceral adipose tissue were excised, weighed, and grinded with liquid nitrogen. Feces samples were collected on day 0 and 40. At the end of our experimental period; the body weight, liver weight, and blood glucose level of sucrose-treated rats were significantly higher (p <0.05) than aspartame and control group. Sucrose showed the lowest level of fto gene expression; yet, the fto gene expression in aspartame group was still lower than the control group. Expression of several genes considered as metabolic syndrome-related biomarkers were measured (fabp4, alt2, and tnf-α); and our data demonstrated that sucrose treatment gave the highest increase in expression level of those genes; while aspartame treatment showed much lower values. Furthermore, sucrose also caused a significant reduction in C. coccoides population; while, the C. coccoides population in aspartame group did not differ significantly compared to the control group.