Prebiotic Effect of Almond May Help in Increasing Beneficial Gut Flora

A study conducted by a team of researchers from the Institute of Food Research, United Kingdom, has demonstrated that almonds, which are associated with numerous health benefits such as cholesterol lowering and anti-diabetic effects, also have the potential to boost the digestive health by increasing the number of beneficial gut bacteria. This study, funded by the Almond Board of California, has been published in the recent online issue of Applied and Environmental Microbiology.

Intestinal flora in adult humans comprises of approximately 1014 bacteria, of more than 400 different species and subspecies. Prebiotics, the non-digestible parts of food, are utilized by the bacterial flora of the digestive system for their growth and activity. Prebiotics stimulate the growth of beneficial bacteria in the gastrointestinal tract and increase resistance against the invading pathogenic bacteria, thus playing a key role in the development of body’s immune system. However, the positive effects of prebiotics on the defense mechanism is observed only if the prebiotics are not digested or absorbed in the upper part of the intestine.

In the current study, G Mandalari, lead scientist at Institute of Food Research, and coworkers, analyzed the prebiotic effects of almonds on in vitro cultures of mixed fecal bacteria. Model Gut, a physical and biochemical simulator of the gastrointestinal tract was used to subject the 2 almond products, i.e., finely ground almonds (FG) and defatted finely ground almonds (DG), to similar conditions found in the stomach and small intestine. To emulate bacterial fermentation in the large intestine, the digested almonds were added to an in vitro batch system, facilitating the scientists in observing its effects on the composition and metabolic activity of the gut bacteria. It was demonstrated that the finely ground almonds increased the number of beneficial intestinal bacteria such as bifidobacteria and Eubacterium rectale, leading to a high prebiotic index. However, defatted finely ground almonds was not associated with any significant difference in the number of gut bacteria, indicating that the prebiotic effect of almonds was not seen with the removal of fat content from the almond preparation. The study suggested that almond lipids were used by the ‘good’ bacteria for their growth, thus forming the base or foundation for the prebiotic effect of almonds.

Several previous studies have shown that the inclusion of nuts, which are rich in fiber, unsaturated fatty acids, and phytonutrients, in the diet reduce the risk of cardiovascular diseases. However, chronic consumption of nuts could lead to weight gain, owing to its high fat content and energy density. 

Earlier, Hollis and Mattes (The British Journal of Nutrition, 2007) conducted a 23-week cross-over design study on 20 women, to determine if a daily intake of 1440 kJ serving of almonds resulted in positive energy balance and body composition change. The participants were asked to consume almonds for 10 weeks without specifying the method of almond inclusion in the diet. This was then followed by the customary diet for an additional 10 weeks, interrupted by a 3-week washout. On measuring energy dissipation researchers found that daily consumption of almonds for 10 weeks did not increase the body weight. This could be attributed to the reduced food intake by the participants, compensating for the energy obtained from almonds. Also, resting metabolic rate, thermic effect of food or total energy expenditure failed to reveal any change. The scientists concluded that the daily intake of 1440 kJ of almonds, which is adequate to provide beneficial effects on cardiovascular risk factors, could be included in the diet without overtly increasing the body weight. However, further studies would be required to analyze the risk of weight gain on consuming almonds in combination with high-fat energy dense foods.

Every year, millions of people worldwide are affected with digestive disorders, ranging from occasional stomach upset to life-threatening colorectal cancers. According to the National Commission on Digestive Diseases, an estimated total economic cost of digestive diseases in US is more than $50 billion annually. 

Almonds, a rich source of vitamin E, decrease the risk of chronic diseases and improve the overall health. Now the current study, which indicates the potential prebiotic effects of almonds in augmenting the digestive health, adds to the previously established nutritional benefits of almond consumption.

This blog post is supported by our sponsor over at Flood Emergency Services. Check out their services here: