Kiwifruit polyphenols may offer prebiotic potential, protect against leaky gut

15-Sep-2021 - Last updated on 15-Sep-2021 at 13:57 GMT

A polyphenolic-rich extract from kiwifruit peel may reduce intestinal permeability associated with a high-fat diet by boosting the levels of beneficial bacteria in the gut, suggests a new study from China.

Data published in the Frontiers in Nutrition indicated that the kiwifruit extract stimulated levels of bacteria such as Lactobacillus and Bifidobacterium in the guts of lab animals, and help counter the development of leaky gut.

“KPE [kiwifruit polyphenol extracts] maybe stimulate Bacteroidete, Lactobacillus, and Bifidobacterium expression, and then down-regulate the expression of inflammatory mediators, thus improving tight junction protein expression. KPE can be used as a functional factor to relieve the damage of intestinal barrier,” wrote researchers from Guizhou Medical University in China.

Prebiotic?

The data indicates that the polyphenol-rich extract may be considered a prebiotic candidate. The major polyphenol in the kiwifruit peel extract was protocatechin, reported the researchers.

Prebiotics are defined as: “A substrate that is selectively utilized by host microorganisms conferring a health benefit” (International Scientific Association for Probiotics and Prebiotics (ISAPP): 2017, Nature Reviews Gastroenterology & Hepatology)

Study details

For the new study, the researchers fed male lab rats a normal diet (control group) or a high-fat diet supplemented with the kiwifruit polyphenol extract (KPE) at a dose of 0, 50, or 100 mg/kg of body weight for nine weeks.

At the end of the study the researchers found that the high-fat diet did increase intestinal permeability and lead to a condition called leaky gut: An undesirable situation when toxic bacterial components can pass from the gut lumen into the blood.

However, supplementing the high-fat diet with the KPE reduced this permeability, and promoted the expression of proteins found in the tight junctions, thereby helping to maintain the intestinal barrier.

The researchers also reported that the relative abundance of Lactobacillus and Bifidobacterium increased, while the relative abundance of Clostridium and Desulfovibrionaceae decreased.

All of these changes also coincided with changes in levels of inflammatory biomarkers, with the KPE showing anti-inflammatory effects. For example, the expression of the anti-inflammatory interleukin-10 (IL-10) was increased, while expression of inflammatory markers such as TLR-2, TLR-4, TNF-alpha and IL-1beta were decreased.

“Supplemented with KPE the intestinal inflammation was improved. Increased intestinal probiotics bacteria components should be useful for preventing TLR or cytokine mediated intestinal damage,” wrote the researchers.

Source: Frontiers in Nutrition
Published online, doi: 10.3389/fnut.2021.702157
“Supplementation of Kiwifruit Polyphenol Extract Attenuates High Fat Diet Induced Intestinal Barrier Damage and Inflammation via Reshaping Gut Microbiome”
Authors: M. Yuan et al.