Majority of us have heard that we should consume yogurt daily to keep our gut healthy. Yogurt contains some live bacteria (Bifidobacteria) that is found to be plentiful in healthy individuals. Two terms are associated with the healthy gut, probiotics and prebiotics. Probiotics are live bacteria that are beneficial to the human gut. Yogurt is a good example of probiotics. (more about probiotics)
Prebiotics are foods that are not being absorbed in the top part of our gut, and after reaching the intestine they become food for the bacteria (such as Bifidobacteria and Lactobacilli). Prebiotics include fruits and vegetables, and also legumes. Studies identified several types of foods that are highest in prebiotics: bananas, apples, whole grains breakfast cereals, garlic, leeks, onions, asparagus, artichoke, beans, wine and coffee. Healthy bacteria in the intestine can combat unwanted bacteria, providing a number of health benefits.
Journal of Agriculture and Chemistry recently published a study that identified and tested an additional prebiotic food that showed a significant increase in Bifidobacteria in overweight but otherwise healthy 47 years old men. Freeze dried blueberries were used as a morning drink for six weeks (equivalent to 1 cup of fresh berries). This study concluded that only one cup of blueberries a day will increase certain populations of Bifidobacteria which will lead to a healthier host, the man.
Previous studies demonstrated that polyphenolic food components including anthocyanins (ACNs) have effect on intestinal microbiota (intestinal organisms). Berries are rich source of ACNs, which together with flavonoids, phenolic acids, folate, minerals and fiber have been shown to be contributors to the healthy microbiota in several vivo studies. Therefore the University of Maine at Orono hypothesized blueberries to be great source of prebiotics.
Twenty overweight (BMI =25) otherwise healthy 47y/o men who did not use any medications nor were on any specific diet were divided into two groups. Group 1 consumed a wild blueberries juice (250mL) every day for 6 weeks. After week 6 there was a washout period, after which, the next 6 weeks these subjects consumed a control treatment (prepared sweetened, colored and flavored water to the taste identical to the blueberry juice). The second group of volunteers were reversed in the order to consumed the control drink (1st) and the wild blueberry juice (2nd) to be able to control for the biases that could be associated with the consumption order. Participants’ feces were investigated for quality and quantity of the bacteria.
Bifidobacteria is a family of bacteria that contains a subdivision of many species of cultures that have been identified in this study. Bifidobacteria could be divided into the three main subgroups, B. longum that is usually found in adults, B. infantis that is usually found in infants and sometimes in adults, but in smaller amounts and B. Dentium.
The study showed a significant increase of B. longum subspecies and B. infantis cell concentration in the feces of volunteers after the wild blueberry drink treatment. This bifidobacterial group was shown to possess an immunologic adjustment, regulation, or potentiation and to relieve symptoms and promote the regression of several gastrointestinal disorders.
In conclusion, blueberries have a lot of health properties such as protecting brain cells, heart and more. This study suggests that about a cup of blueberries a day will help fight gastrointestinal disorders and also possesses immunologic properties.