Medical Bulletin 01/ April/ 2024

Here are the top medical news for the day:

Kombucha tea may be linked to fat loss, finds study

According to a research conducted at The University of North Carolina at Chapel Hill and published in the journal PLOS Genetics, drinking kombucha tea may help reduce fat accumulation and lower triglyceride levels.

When a person has too much fat stored within their body, particularly triglycerides, it can increase their risk for several health conditions, including cardiovascular diseases such as atherosclerosis, stroke, and heart failure.

Kombucha tea is a fermented drink made from black tea and a symbiotic culture of bacteria and yeast. The addition of bacteria and yeast also makes it a probiotic beverage.Previous animal and small-scale human studies have suggested that kombucha may be helpful in the treatment of several diseases, including diabetes, liver disease, and gut health.Other animal and pre-clinical research has found that kombucha may assist with different aspects of cardiovascular health, such as lowering cholesterol levels and high blood pressure.

In the study, researchers used C. elegans to investigate whether intestinal colonisation with Kombucha-associated microbial species rewired host metabolism and developed a reproducible method to culture animals on lawns of KT microbes consisting of microbes found in all commercial and homebrewed KTs.

The results revealed that animals feeding on KT microbes accumulate significantly less fat than animals consuming either an E. coli diet, any of the individual three KT-associated microbial species, or a simple non-fermenting mix of these three species. Furthermore, the data suggested that KT consumption reduces fat storage by modulating host lipid metabolism pathways rather than restricting caloric intake.

“We were very surprised to find that the probiotic microbes in kombucha tea could colonize the worm gut and stimulate a fasting-like metabolic response in the host, which occurred despite the fact that these animals showed no defects in intestinal nutrient absorption. Incredibly, this response was only seen in animals consuming microbes isolated from a long-term, fully fermented kombucha tea culture and not a simple mix of non-fermenting kombucha-associated microbes. This observation suggested that microbial metabolites produced during the fermentation process could be shaping host metabolic pathways,” said Rob Dowen, PhD, professor of cell biology and physiology in the School of Medicine at The University of North Carolina at Chapel Hill and lead author of this study.

Reference: Rachel N. DuMez-Kornegay,Lillian S. Baker,Alexis J. Morris,Whitney L. M. DeLoach,Robert H. Dowen; Kombucha Tea-associated microbes remodel host metabolic pathways to suppress lipid accumulation; Journal: PLOS Genetics; https://doi.org/10.1371/journal.pgen.1011003

Low fiber intake may trigger inflammatory bowel disease, says study

A study published in the journal Cell host and Microbe, found that fibre plays a significant role in the interplay between gut microbes and the mucus lining of the digestive system.

Fiber promotes the development of healthy mucus thickness and inhibits inflammation. For people who are born without interleukin-10, an IBD-associated cytokine, IBD typically develops in early infancy or childhood.Irritable bowel disorder (IBD), which can manifest as either ulcerative colitis or Crohn’s disease, develops out of inflammation in the gut or digestive tract, leading to a range of sometimes painful issues with digestion. Scientists have not been able to identify the root cause of this disorder yet, but a recent study suggests a connection between genetics, diet, and gut microbiota that could lead to the development of IBD.

The study used mice who also lacked interleukin-10. A fibre-free diet was shown to encourage the growth of mucin-degrading bacteria, which consume the mucus layer in the digestive system, reducing the barrier that the mucus provides for the lining of the gut. The mice who ate a high-fibre diet had significantly less inflammation.However, when researchers fed mice the EEN diet formula, some of them had less inflammation than those with a fibre-free diet.

The findings revealed thathealthy gut bacteria play a crucial role in both our immune and digestive systems. Certain beneficial bacteria strengthen our intestinal barrier, preventing harmful substances from entering our gut. Weakness in this barrier, known as "leaky gut," often seen in IBD and IBS patients, can cause inflammation or indicate other gut imbalances. Additionally, these bacteria aid in producing neurotransmitters essential for proper brain function and emotional well-being.

“A low-fiber diet may be recommended for people with IBD during acute (active) flare-ups when the inflammation in their gut intensifies. Fiber can be hard to break down, and can therefore exacerbate existing irritation in the gut or gut lining which can contribute to certain symptoms like diarrhea, stomach pain, rectal bleeding, bloating, or even fever. During flare-ups, it’s best to avoid anything that may add to the existing inflammation in the gut,” said Melanie Murphy Richter, a registered dietitian nutritionist.

Reference:Gabriel Vasconcelos Pereira, Marie Boudaud, Mathis Wolter, Kathryn A. Eaton, Mahesh S. Desai, Eric C. Martens; Opposing diet, microbiome, and metabolite mechanisms regulate inflammatory bowel disease in a genetically susceptible host; Journal: Host cell and Microbe; DOI:https://doi.org/10.1016/j.chom.2024.03.001

Diets rich in antioxidants associated with reduced type 2 diabetes risk, finds study

Scientists at the Karolinska Institute in Sweden conducted a systematic review and meta-analysis to determine the relationship between dietary antioxidant intake and type 2 diabetes risk.

The study was published in the journal Advances in Nutrition.

Type 2 diabetes is a metabolic disease marked by insulin secretion issues and elevated blood glucose levels. Its global prevalence exceeds 10%, fueled by poor dietary choices and sedentary lifestyles. Diet plays a pivotal role in regulating metabolism, among other lifestyle factors. Research suggests that adopting healthy eating patternscan substantially lower the risk of developing type 2 diabetes. These diets emphasize a higher intake of plant-based foods rich in antioxidants, including vitamins C, E, and beta-carotene, which are associated with improved metabolic health and reduced diabetes risk.

In the study, the scientists searched various electronic databases to identify studies investigating the association between dietary intakes, circulating levels, or supplementation of vitamin C, E, and beta-carotene and type 2 diabetes incidence or insulin resistance/sensitivity and beta cell function in non-diabetic individuals.The final screening led to the identification of 25 prospective observational studies and 15 randomized controlled trials. Moderate and serious risks of bias were observed in 21 and 4 observational studies, respectively. Among randomized controlled trials, 13 had a low risk of bias, and 2 had some concerns.

The study found that higher dietary and circulating levels of vitamins C, E, and beta-carotene are associated with a reduced risk of type 2 diabetes. However, supplementation with these antioxidants did not show a protective effect against diabetes. These vitamins exert their anti-diabetic effects through their antioxidant properties. Vitamin C, found in fruits and vegetables, removes free radicals in the body's water-soluble compartments and regenerates vitamin E which is present in nuts, seeds, and vegetable oils, prevents lipid peroxidation and protects cell membranes. Beta-carotene, found in fruits and vegetables, protects lipid components of the body from free radical damage, similar to vitamin E.

Reference:Anna-Maria Lampousi. 2024. Vitamins C, E, and beta-carotene and risk of type 2 diabetes: a systematic review and meta-analysis. Advances in Nutrition; https://www.sciencedirect.com/science/article/pii/S2161831324000450