Grapes offer a range of health benefits, including boosting immunity, promoting cardiovascular health and regulating blood sugar levels as they are rich in potassium. But how many grapes should one eat in a day? Researchers say three servings would be ideal.

The study, published in the journal Scientific Reports, has found that grapes can also have a positive impact on gut health by increasing the abundance of beneficial gut bacteria, giving us yet another reason for incorporating grapes into the dietary routine.

How important is the gut microbiota?

The gut microbiota is crucial for human health, impacting various aspects such as digestion, immune function, nutrient absorption and even influencing conditions like obesity, diabetes and mental health.

Researchers, considering the impact of different nutrients on the microbiome, have turned their attention to specific foods like grapes to explore their potential benefits in promoting the growth and diversity of the gut microbiome.

Besides the known benefits of grapes for heart health, memory improvement and protection against colon cancer, researchers have found that they can also help decrease inflammation in the body.

"Since we know that diet can modulate the gut microbiome, and we know that dietary grapes can have some effects on health, it is reasonable to ask: can grapes modulate the gut microbiome? This may be related to the overall mechanism of action," John M. Pezzuto, dean and professor of pharmaceutics of the Western New England University College of Pharmacy and Health Sciences, explained to Medical News Today (MNT).

How do three servings of grapes impact microbiome production?

Researchers tracked 41 healthy people, with only 29 of them completing the study. Out of the participants, 22 were female (53.7%) and 19 were male (46.3%). The ages of the participants ranged from 20.9 to 55.7 years, with an average age of 39.8 years.

When the participants were made to consume grapes for two weeks, certain types of gut bacteria, such as Holdemania spp., decreased, while others like Streptococcus thermophiles increased.

Some exhibited changes in their microbiome even 30 days after stopping grape consumption, suggesting that the effects of eating grapes can be delayed.

"It is logical to think some of the microorganisms found the grapes desirable and flourished, whereas others did not. The matter is very complex, but also, if one member of the microbial community begins to flourish, that may in itself affect the abundance of others," Pezzuto told MNT.

"Since each of the microbial members within the community have their own enzymes that participate in various metabolic pathways, shifting abundance will shift enzyme and pathway levels, either up or down," he added.

Concentrate, made from grapes like these, is one of the products in question. AFP / SAFIN HAMED