Summary: Consuming a hand full of almonds every day increases the production of butyrate, improves the metabolism of bacteria, and positively affects health.
source: King’s College London
A team of King’s researchers investigated the effect of whole and ground almonds on the composition of the gut microbiome.
The study, published today in American Journal of Clinical NutritionFunded by the Almond Board of California.
The gut microbiome is made up of thousands of microorganisms that live in the gut. These substances play a vital role in the digestion of nutrients and can have a positive or negative impact on our health, including our digestive and immune systems.
The mechanisms of how gut microbiomes affect human health are still being investigated, but evidence suggests that eating certain types of food can positively affect the types of bacteria in our gut or what they do in our gut.
The researchers recruited 87 healthy adults who were already eating less than the recommended amount of dietary fiber and who ate typical unhealthy snacks (such as chocolate and chips).
Participants were divided into three groups: one who changed their snacks for 56g of whole almonds per day, another for 56g of ground almonds per day, and the control group ate an energy-matched cake as a control. The trial lasted four weeks.
“Part of the way gut bacteria affect human health is through the production of short-chain fatty acids, such as butyrate. These molecules act as a fuel source for cells in the colon,” said lead author Professor Kevin Whelan, Head of the Department of Nutritional Sciences. Other nutrients in the intestines, help balance the immune system.
The researchers found that butters were significantly higher among those who ate almonds compared to those who ate cake. Butyrate is a short-chain fatty acid that is the main source of fuel for the cells lining the colon.
When working effectively, these cells provide an ideal condition for the gut microbes to thrive, the gut wall to be strong and not leaky or inflamed, and nutrients to be absorbed.
No significant difference was observed in gut transit time – the time it takes food to travel through the gut – however, those eating whole almonds had 1.5 extra bowel movements per week compared to the other groups. These findings suggest that eating almonds can also benefit those who suffer from constipation.
Tests showed that eating whole and ground almonds improved people’s diet, with higher intakes of monounsaturated fatty acids, fiber, potassium and other important nutrients than the control group.
Professor Whelan added: “We believe these findings suggest that almond consumption may benefit bacterial metabolism in a way that has the potential to affect human health.”
About this diet and microbiome research news
original search: open access.
“Effect of almond and almond processing on gastrointestinal physiology, luminal microbiota and gastrointestinal symptoms: a randomized controlled trial and chewing study.Written by Kevin Whelan et al. American Journal of Clinical Nutrition
Effect of almond and almond processing on gastrointestinal physiology, luminal microbiota and gastrointestinal symptoms: a randomized controlled trial and chewing study.
Almonds contain fats, fibers, and polyphenols and possess physicochemical properties that influence the bio-accessibility of nutrients, presumably affecting gut physiology and microbes.
Check the effect of whole almonds and ground almonds (almond flour) on faecal bifidobacteria (primary result), intestinal microbiota composition and transit time.
Healthy adults (n = 87) participated in a parallel 3-arm randomized controlled trial. Participants were given whole almonds (56 g/day), ground almonds (56 g/day) or isotonic control cakes in place of their usual snacks for 4 weeks. Composition and diversity of gut microbiota (16S rRNA gene sequence), short-chain fatty acids (gas chromatography), VOCs (gas chromatography-mass spectrometry), gut transit time (radio-motility capsule), stool output and gut symptoms (7 day diaries) ) at baseline and end point. The effect of almond shape on particle size distribution (PSD) and expected lipid release was measured in a subgroup (n = 31).
An adjusted intention-to-treat analysis was performed on 79 participants. There were no significant differences in the abundance of fecal bifidobacteria after ingestion of whole almonds (8.7%, SD 7.7%), ground almonds (7.8%, SD 6.9%) or control (13.0%, SD 10.2%). q = 0.613). Consumption of almonds (whole and ground) resulted in higher butterfat (24.1 μmol/g, SD 15.0 μmol/g) compared to the control (18.2 μmol/g, SD 9.1 μmol/g; s = 0.046). There was no effect of almonds on gut microbiota at the family level or diversity, gut transit time, stool consistency or gut symptoms. Almond shape (whole versus ground) had no effect on the study results. Ground almonds resulted in significantly smaller PSD and higher expected lipid release (10.4%, SD 1.8%) compared to whole almonds (9.3%, SD 2.0%; s = 0.017).
Consumption of almonds has a limited effect on the composition of the gut microbiota but increases butyrate concentrations in adults, indicating positive changes in the functions of the microorganisms. Almonds can be incorporated into the diet to increase fiber consumption without causing intestinal symptoms.