Study shows GTK improves GI health, aiding in digestion and supporting weight loss.

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A recent study has shed light on how green tea kombucha (GTK) can improve certain aspects of digestive health and support weight loss efforts. Conducted as a randomized controlled trial, the research investigated GTK’s effects on individuals with excess weight who were following a calorie-restricted diet. Participants drank 200 mL of GTK daily, while a control group followed the same diet but without kombucha. The study primarily focused on gut health, metabolic markers, and changes in specific metabolites.

Fermented foods like kombucha have grown popular due to their potential health benefits, particularly for gut health. GTK, made by fermenting green tea with a blend of bacteria and yeast, contains various bioactive compounds including antioxidants and probiotics. These components have been associated with benefits ranging from improved digestion to enhanced immune function. While kombucha’s effects have been widely touted, scientific evidence in humans, especially in people with higher body weight, has been limited. This study set out to examine how GTK might impact individuals already working toward weight loss.

The participants in the study included both men and women with a body mass index (BMI) of at least 27 and body fat levels above 30% for women and 25% for men—individuals most likely to experience metabolic benefits from diet changes. The GTK consumed in the study was carefully prepared in-house to standardize its composition and ensure it provided consistent probiotic content. The team monitored each participant’s weight, body composition, gut health, and metabolic markers over ten weeks.

GTK’s effects on gut microbiota were not significant; however, subtle changes were observed. Beneficial bacteria like Romboutsia increased slightly, while potentially harmful Alistipes decreased. While these shifts weren’t large enough to draw major conclusions about microbiota diversity, they suggest GTK may encourage a healthier balance of gut bacteria over time. The trial also revealed GTK’s impact on gastrointestinal symptoms. Participants reported more regular bowel movements and relief from symptoms like hard stools and a feeling of incomplete evacuation. GTK drinkers saw greater improvements in these areas compared to the control group.

In addition to gastrointestinal improvements, the study looked at blood metabolites to assess how GTK might influence metabolic health. Among those consuming GTK, certain beneficial metabolites associated with amino acid and fatty acid metabolism increased. These changes may be linked to GTK’s known anti-inflammatory and antioxidant properties, suggesting that GTK could support metabolic health beyond just weight loss. However, GTK did not notably alter more direct indicators like intestinal permeability, which measures gut barrier function.

Both the control and GTK groups experienced similar weight loss and reductions in body fat. These improvements were attributed to the calorie-restricted diet, with GTK providing additional support through enhanced digestive health. The control group, however, showed less favorable changes in intestinal pH and markers of gut permeability. This suggests that while GTK may not directly change the gut’s structural integrity, it might help prevent the minor adverse effects on the gut lining that sometimes accompany weight loss efforts.

Ultimately, GTK appears to offer a gentle boost to gut health and metabolic wellness. Though it did not lead to extensive changes in gut microbiota or body composition, GTK did ease certain gastrointestinal symptoms and supported a healthier metabolic profile in participants, suggesting it could be a valuable addition to a well-balanced diet for those hoping to lose weight.

Sources:

Green tea kombucha could transform your gut and boost your weight-loss journey

The Impact of Green Tea Kombucha on the Intestinal Health, Gut Microbiota, and Serum Metabolome of Individuals with Excess Body Weight in a Weight Loss Intervention: A Randomized Controlled Trial

Testing done by supplement manufacturer NOW shows that serious quality problems persist among SAMe products marketed by lesser-known brands. Only three of the 24 products tested met label claim for potency. 

This is the 19^th round of tests that NOW has conducted on supplements marketed by lesser-known brands on Amazon. As in the other rounds of testing, NOW purchased two bottles of each product. The company tested one sample in its in-house laboratory and sent the other to a Eurofins lab for independent confirmation. As has become common practice, NOW also tested one of its own SKUs along with the others. 

SAMe, or S-adenosyl-L-methionine, is a compound found naturally in the body, helping to produce and regulate hormones and maintain cell membranes. As a supplement, SAMe is often used for mood support, joint health and liver support. 

NOW noted SAMe is considered an expensive ingredient, which tends to increase the likelihood of economic adulteration, in which brands substitute less expensive material for an expensive bioactive ingredient. 

Second round of testing almost as bad as first 

This is the second time that NOW has tested SAMe products for sale on Amazon. In the first round of testing done in 2020, NOW tested 11 products and found that all of them were low potency, with two of the brands having none of the bioactive ingredient. 

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In this round of testing, NOW bought two bottles each of 23 suspect SAMe supplements, and the company included its own SAMe SKU for comparison. 

Only three of the products met label claim, as did the NOW product. The rest were significantly understrength, and six brands had no detectable levels of SAMe in the bottles. 

Two of the brands tested were gummy products.  Gummies are popular with consumers but are not an appropriate delivery system for every bioactive substance as the high temperature processing required can damage delicate ingredients.  

Is SAMe appropriate for gummies? 

NOW said it was interested in testing the gummies since SAMe has well known stability problems. That issue has led at least a few ingredient suppliers to offer enteric coated beadlet versions of the ingredient. 

Neither of the gummy products contained any detectable levels of SAMe. 

Some patterns have emerged from NOW’s testing. Five brands that market low-potency products have shown up frequently: aSquared, Healthy Way, Mono Herbs, Nasa B’Ahava and Superior Health. Mono Herbs, which was included in the 2020 round of SAMe testing, tested at zero potency for the second time in four years. 

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The aSquared brand is a standout among the repeat offenders. Over the years, NOW has tested 13 different lots of the company’s products in various categories and has never found one that met label claim. 

As has become standard practice, NOW forwards the test results to Amazon. The online retailing giant has never responded to NOW concerning NOW’s findings. 

Amazon did not respond to a request for comment for this story. 

SupplySide Supplement Journal contacted those repeat offender brands for which contact information could be found. No responses were received in time for publication.