Consumption of fermented soy milk has previously been found to increase healthy microbiota, such as Bifidobacteria and Lactobacilli, and to decrease the pathogenic ones, such as Clostridia, in healthy individuals.
The fermented soy drink Q-CAN contains a combination of isoflavones such as Genistein and Daidzein, amino acids, trace elements, minerals, bioactive peptides and branched-chain fatty acids which have been shown to exert health benefits on the host via alterations in key bacteria.
The authors of the current study aimed to discover what specific bacterial changes are induced in the oral and intestinal microbiome by Q-CAN in both lean and obese individuals.
Twenty subjects were recruited, mostly from the campus of Yale University, including 10 lean (3 males, 7 females, mean age 32 years, mean BMI 22 Kg/m2 ) and 10 obese (7 males, 3 females, mean age 45 years, mean BMI 34 Kg/m2).
The participants attended the lab 11 times to provide saliva and stool samples, weekly at first. After the 3rd visit they started the Q-CAN consumption (237 ml) twice daily for four weeks until visit seven. At the 7th visit they stopped the Q-CAN consumption and then attended bi-weekly to identify if there were any sustained changes.
Results
During the beverage consumption, at phylum level, the researchers found an increase in Actinobacteria in the stool of lean individuals, and there was an increase in Fusobacteria in obese individuals. At a genus level there was an increase in Blautia, Bifidobacterium and Staphylococcus in the stool of lean individuals.
When comparing the lean and obese populations, Q-CAN consumption resulted in a greater number of changes in the lean compared to the obese participants.
The authors suggest this may be due to the microbiota of obese individuals having less diversity and therefore less opportunity for the ingredients to interact with a range of microbes.
The report says the increase in Actinobacteria in lean individuals is of interest because Actinobacteria are one of the four major phyla of gut microbiota and have a crucial role in maintaining gut homeostasis. Within this phylum, the increase was found to be in the family Bifidobacteria which offer a range of health benefits.
The report notes: "Bifidobacteria have high production of short chain fatty acids (SCFA), and one of the beneficial effects of this is in the maintenance of gut barrier due to the production of butyrate. Bifidobacteria can protect the host from enteropathogenic infections, such as entero-haemorrhagic Eschericl1ia coli and Shigella, and this thought to be due their high production of acetate and the biotransformation of nutrients in the diet.
"This occurs via the fermentation of large polysaccharides, oligosaccarides, unabsorbed sugars and fibers. This results in the release hydrogen, carbon dioxide and SCFAs. It furthermore results in the degradation of proteins, the regulation of lipid metabolism, and the absorption and biosynthesis of vitamin K, iron, calcium and magnesium.
"Bifidobacteria are also important in the maintenance of a tolerogenic immune environment, and this is thought to be through the stimulation of intrahepatic lymphocytes. This is supported by an increase in gut permeability that leads to the translocation of LPS into the serum when there is a decrease in the number of Bifidobacteria. This provides immune stimulation, and sustains chronic inflammatory conditions, such as insulin resistance, diabetes and liver diseases."
A significant increase in the phylum Actinobacteria and the family Bifidobacteria in the stool was not seen in obese individuals, however there was a trend in that direction
The report also notes that the increase in Blautia is of interest as it has been associated with several positive health features including nutrient assimilation, immunological health, lower amount of visceral fat, and reduced risk of graft versus host disease.
In the saliva of lean individuals, there was an increase in family Veillonellaceae (genera Veillonella, Acidaminococcus, and Megasphaera) while on Q-CAN. Members of the family Veillonellaceae are of particular interest for their probiotic effects.
Source: BMC Nutrition
Dioletis, E., Paiva, R., Kaffe, E. et al.
"The fermented soy beverage Q-CAN® plus induces beneficial changes in the oral and intestinal microbiome"
https://doi.org/10.1186/s40795-021-00408-4
