Reviving Tradition: Fermented Milk Products as a Source of Gut-Healthy Probiotics for Obesity

Posted on December 17, 2024   by Dr Muhammad Nadeem Khan

Dr Muhammad Nadeem Khan takes us behind the scenes of their latest publication 'Dairy-based multi-strain probiotic community successfully mitigated obesity-related gut microbiota dysbiosis in vitro (CoMiniGut)' published in Journal of Medical Microbiology.

I am Dr Muhammad Nadeem Khan, currently a postdoctoral researcher at the Department of Cell Biology and Genetics, Shantou University Medical College in China. My research journey began in 2015, under the mentorship of Professor Dr Muhammad Imran at the Department of Microbiology, Quaid-I-Azam University, Islamabad, Pakistan. Professor Imran’s work on gut microbiota, food and human health greatly influenced my decision to pursue this field. I further expanded my research experience at the Department of Food Sciences, University of Copenhagen, Denmark, under the guidance of Professor Dennis. Specialising in microbiology and its intersection with human health, my recent work has focused on how probiotics can modulate gut health, particularly in relation to obesity-related gut microbiota dysbiosis. Our latest study, published in the Journal of Medical Microbiology, explores the promising role of multi-strain probiotics in restoring balance to the gut microbiota in obesity.

In 2015, when I joined Dr Imran’s lab, the field of gut microbiota was still in its early stages, and the idea of harnessing the microbiota to improve health was just beginning to gain traction. We were eager to explore innovative ways to understand and improve gut health, and one concept that emerged during our brainstorming sessions was the idea of "resetting" the gut microbiota, similar to how we might reset a malfunctioning mobile phone. Inspired by this idea, we began to wonder: could we restore balance to the gut microbiota and potentially alleviate underlying health issues by applying a similar concept of "resetting"?

While directly “resetting” the gut microbiota proved challenging, we pivoted to exploring fasting as an alternative. Fasting has long been associated with a range of health benefits and has been practiced for centuries. We decided to investigate whether fasting could positively impact the gut microbiota, which became the focus of my master's thesis. Our experiments confirmed that fasting has a beneficial effect, helping to normalise the gut microbiota. These findings were published and presented at several conferences, contributing new insights to the growing body of microbiome research.

At the same time, we began to investigate the role of traditional dairy products in gut health. Specifically, we focused on a traditional fermented dairy product, Dahi, widely consumed in Pakistan for cooking and medicinal purposes. Despite concerns about hygiene in its production, Dahi has been part of the local diet for decades and is believed to offer a variety of health benefits, especially in managing chronic diseases. Our research revealed that people who consumed Dahi experienced better health, even though it was made under less stringent hygienic conditions than modern dairy products.

This finding led us to hypothesise that Dahi might contain a diverse range of beneficial bacteria. We isolated probiotics from the dairy and found that they had potential health benefits. Encouraged by these results, we next explored whether these probiotics could specifically target obesity, a growing global health concern. However, as we delved deeper into the complexities of the gut microbiota, we realised that the microbiota is a highly diverse and dynamic community, making it unlikely that a single probiotic strain would have a significant impact on such a complex system.

This realisation prompted us to shift our approach. Rather than focusing on a single strain, we decided to use a compatible microbial community comprising multiple strains, aiming to modulate the gut bacterial community as a whole. To explore this further, we revisited Dahi, a rich source of diverse probiotics. We isolated and characterised bacteria from Dahi and tested its impact on obesity-related microbiota dysbiosis using an in-vitro intestinal model.

The Multi-strain probiotic community (MSPC) demonstrated significant potential in modulating gut microbiota in both lean and obese individuals. In lean samples, bacterial counts generally decreased, while in obese samples, they increased significantly. MSPC improved microbial diversity, enhancing α-diversity in most samples and shifting β-diversity toward healthier patterns. At the phylum level, MSPC reduced Proteobacteria—a marker of gut imbalance—in lean individuals, while increasing beneficial Firmicutes in obese samples. At the genus level, it promoted beneficial bacteria like Lactobacillus and Bifidobacterium, while suppressing harmful ones such as Klebsiella and Enterobacter. Additionally, MSPC influenced microbial metabolites, enhancing anti-inflammatory compounds like butyrate, which supports gut health and immunity. These findings underscore MSPC's potential role in personalised interventions for gut microbiota dysbiosis and obesity management.

By adopting a more holistic approach, we are now in a better position to explore dietary and lifestyle interventions that could improve gut health on a larger scale. This research holds great promise, particularly in the development of probiotic-based treatments and dietary strategies aimed at restoring balance to the gut microbiota and addressing issues like obesity. The combination of traditional foods like fermented milk products and modern scientific approaches offers exciting potential for improving gut health and addressing obesity-related microbiota dysbiosis. The future of this research is full of promise, and I look forward to continuing to explore how we can use these natural resources to improve human health.