News

Talking about our gut health daily is more important now than before. This is because the gut is often referred to as “our second brain”. The reason for this is that the gut influences our overall wellbeing.  The state of our gut microbiome affects every aspect of our life, from the moment we eat food and digestion takes place, nutrient absorption to our immune function and mental health.  Among the scientists making strides in this field to uncover deeper connections between gut health and chronic diseases is Dr Humphrey Andalo Mabwi, a Regional Scholarship and Innovation Fund (Rsif) graduate, whose PhD work revolved around Design of synthetic human gut microbiota ecosystem models for screening novel prebiotics from phytochemicals. Dr. Mabwi also won the best young researcher award at the just-concluded Kenya National Research Festival 2024.

The 38-year-old Kenyan is a lecturer Biology at Masinde Muliro University of Science and Technology and graduated with a Ph.D. in Molecular and Biotechnology at the Sokoine University of Agriculture and did his laboratory research work at Korea Institute of Science and Technology.

Rsif is the flagship programme of the Partnership for Skills in Applied Sciences, Engineering, and Technology (PASET), managed by the International Centre of Insect Physiology and Ecology (icipe) as the Regional Coordination Unit.

 Why study gut microbiota?

 Q: What inspired you to focus on synthetic gut microbiota ecosystems, and can you tell us a little bit about your research focus in simple terms?

A: Human gut microbiota has been reported to be associated with the occurrence and development of several chronic metabolic diseases, such as obesity, diabetes mellitus, and cancer. However, its is incredibly complex, with hundreds of bacterial species interacting in ways that are hard to fully comprehend. How to easily study the complex gut microbiota inspired me start working with synthetic human gut microbiomes. Synthetic ecosystems offer a simpler, controlled environment for easy investigation of complex human gut microbiota in diseases and health. Synthetic gut microbiome research is all about creating simplified versions of the bacteria that live in our gut to easily study them in a controlled way. In our stomachs and intestines, there are trillions of bacteria that help us digest food, fight off infections, and even influence our mood and brain function. But because the natural gut is so complex, it’s hard to figure out exactly how each type of bacteria works. So, creating synthetic versions of human gut microbiota ecosystem comprising key important types of bacteria, can help to understand how bacteria in our gut affect health and disease. This can also help in development of better treatments and in creation of prebiotics that can restore balance to the gut.

Q: Why is studying gut microbiota important for our health?

A: The gut microbiota is a key player in digestion, immune function, mental health, and disease prevention. By studying it, it’s possible to develop better treatments for various health conditions and improve overall well-being.

Q: What steps are involved in designing synthetic gut microbiota ecosystem?

A: Designing a synthetic gut microbiota ecosystem involves selecting the right bacteria, growing them in lab conditions in the correct medium, assembling them to form a community, and then culturing them in a bioreactor that mimics the human gut, and then testing how they interact and affect health.

Q: Please tell us what are phytochemicals in layman’s language and why they are significant for gut health?

A: Phytochemicals are natural substances produced by plants to protect them from things like bugs and diseases. When we eat fruits, vegetables, grains, and other plant foods, we also get these helpful compounds. Phytochemicals are not essential nutrients like vitamins or minerals, they can still do a lot of good things for our health. By influencing gut microbiota, reducing inflammation, and maintaining the gut barrier, phytochemicals play a vital role in promoting overall gut health, which is increasingly linked to mental health and immune function.

Q: Can you describe the methods you use to screen potential prebiotics from these phytochemicals?

A: The process of designing these synthetic gut microbiota ecosystems is thorough. It starts with selecting the right bacteria, growing them under controlled lab conditions, and then assembling them into a community that mimics the human gut. From there, we test how they interact and affect health, using various bioreactors that simulate the gut environment.

Through these ecosystems, we can screen potential prebiotics, which are compounds that stimulate the growth of beneficial bacteria in the gut.

We select phytochemicals based on their known bioactive properties, create a synthetic microbiota to simulate the human gut, and then introduce these compounds at physiologically relevant concentrations. We monitor changes using advanced techniques like 16S rRNA gene sequencing and analyze the production of short-chain fatty acids (SCFAs), which are critical for gut health.

Promising findings

 Q: What have been some of your most surprising findings in this research focus?

A: Stability of synthetic microbial communities: synthetic microbial communities displayed a surprising level stability during my experiments. It was surprising also that I managed to replicate my results obtained with synthetic microbial communities using animal model. The same result observed with synthetic microbial communities was also observed using a mouse. This can offer new insights into designing robust probiotic or prebiotic therapies that can persist and function over time.

Q: How do these synthetic ecosystems help in understanding the effects of diet on gut health?

A: Synthetic gut microbiomes provide a versatile platform for dissecting the complex interactions between diet and gut health. They enable researchers to pinpoint specific dietary influences, understand microbial responses, and ultimately guide strategies for improving health through diet.

Q: What potential health benefits could arise from your research?

A: Identifying effective prebiotics can help promote a more diverse gut microbiome, which is associated with better overall gut health and resilience against diseases. Through influencing the gut microbiota composition and function, prebiotics derived from phytochemicals may positively affect the gut-brain axis, potentially alleviating symptoms of anxiety, depression, and other mood disorders. By promoting a healthy gut microbiome and SCFA production, prebiotics may lower the risk of colon cancer through mechanisms like improved gut barrier function and reduced inflammation. The identification of effective prebiotics can lead to the development of functional foods and supplements that specifically target gut health, improving public health outcomes.

Q: What challenges do you face when creating these synthetic ecosystems?

A: The human gut microbiome consists of hundreds to thousands of species, each with unique metabolic capabilities. Replicating this complexity in a synthetic model can be difficult. Secondly, the synthetic gut ecosystem must replicate the specific conditions of the human gut, including pH, temperature, oxygen levels, and nutrient gradients. Achieving these conditions can be technically challenging. Synthetic systems can also be susceptible to contamination from unwanted microbes, which can disrupt the intended microbial community. I failed to simulate interactions with the host’s immune system, gut epithelium, and other physiological components that influence microbial behavior and metabolism in my model.

 Influencing dietary recommendations

 Q: Looking ahead, how do you envision this research influencing future dietary recommendations or probiotic development?

A: By identifying specific prebiotics that beneficially affect distinct microbial profiles, synthetic gut models can help develop personalized dietary strategies that cater to individual microbiome compositions and health needs. Understanding how different individuals respond to various prebiotics can lead to targeted dietary interventions that optimize gut health based on individual microbiome characteristics. Additionally, findings from synthetic gut studies can contribute to the development of evidence-based dietary guidelines that incorporate specific prebiotics for improving gut health, reducing disease risk, and promoting overall well-being. Synthetic gut models will enable the screening of a broader range of phytochemicals and natural compounds for their prebiotic potential, leading to the discovery of new prebiotic sources beyond conventional options like inulin and oligosaccharides. My research can encourage the incorporation of diverse plant-based foods into dietary recommendations, promoting broader dietary patterns beneficial for gut health.

Q: How can the average person apply insights from your research to improve their gut health?

A: Focus on incorporating a wide range of dietary fibers into his/her diet, as different fibers can act as prebiotics. Foods high in fiber include fruits, vegetables, whole grains, legumes, nuts, and seeds. Encouraged to focus on a diet rich in fruits, vegetables, and whole grains provides a variety of phytochemicals and fibers that can act as prebiotics. Should aim for at least half of their plate to be filled with plant-based foods at each meal. Include foods high in phytochemicals, such as berries, green tea, and spices like turmeric, which may provide additional health benefits.

Take home message

Q: What message would you like to convey to those interested in nutrition and gut health based on your findings?

A: Let us embrace a diverse diet rich in various fibers and phytochemicals. Foods like fruits, vegetables, whole grains, and legumes not only nourish our bodies but also serve as food for our beneficial gut bacteria. We should not hesitate to experiment with less common prebiotic sources. Ingredients like, garlic, onions, can offer substantial benefits in supporting their gut microbiome. We should consider incorporating foods that contain both prebiotics and probiotics. This synergy can enhance the growth and activity of beneficial bacteria, promoting a healthier gut environment. We should keep ourselves updated on the latest research findings and dietary recommendations related to gut health.

 As more research continues to unfold, the future of gut health—and our understanding of it—looks very promising. Dr. Mabwi’s work could lead to new strategies for optimizing our microbiota, promoting a healthier, more balanced gut for people not only in Kenya but worldwide