“There’s a lot of interest in harnessing the gut microbiome for the betterment of our health, but it’s a complex system we still need to understand much better,” says Professor Alice Lichtenstein.
Lichtenstein’s research at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, US, focuses on the interplay between diet and cardiometabolic risk factors, where the gut microbiome also has a role.
Lichtenstein holds an Honorary Doctorate at the University of Eastern Finland, where she has visited annually, since the 1990s, to give PhD students of nutrition lectures on topics spanning from study design to cardiovascular diseases and the microbiome. During her this year’s visit to Kuopio in August, she also acted as the Opponent at the PhD defence of Johnson Lok, MSc, during her visit in Kuopio.
Lok’s preclinical study showed how gut dysbiosis is involved in the development of metabolic dysfunction-associated steatotic liver disease (MASLD). Advanced gut microbiome therapeutics, combined with dietary changes, improved MASLD symptoms in a mouse model, reducing liver fat and blood cholesterol, as well as promoting weight loss and microbial diversity.
“Johnson had done a stellar job, and because I work more with humans, I gained a deeper appreciation of how important it is to start adjudicating potential therapies in an animal model,” Lichtenstein says.
Testing a microbiome sampling pill
One of Lichtenstein’s own ongoing research projects compares the effects of fat free dairy products, both unfermented and fermented, to full-fat dairy products in a randomised crossover trial. “There has been controversy about dairy fat – whether it’s equivalent to other animal fats in terms of cardiovascular disease risk factors. We are interested to see how differences in dairy fat content and fermentation affect these measures, and if so, are the changes related to the gut microbiota.”
Her team is also about to start an NIH-funded proof-of-concept study to test an ingestible mini-pill designed to collect gut luminal contents before reaching the colon. This technology, if demonstrated to be efficacious, will allow researchers to track the evolution of the gut microbiota, from the upper gastrointestinal track to the colon. Developed at Tufts University School of Engineering and already tested in dogs at the Tufts University School of Veterinary Medicine, the mini-pill is expected to advance the understanding of microbial species populating the entire length of the gastrointestinal tract.
“We know that diet and some drugs affect the gut microbiome. This has been studied mostly in faecal samples, but they don’t tell us what happens higher up in the gastrointestinal tract and if there are opportunities to modify the gut microbiota to improve health outcomes.”
The participants in the study will be provided with two entrées per day containing either regular meat or plant-based meat alternatives, and then switched. This intervention was chosen because it has previously been established to have different effects on the gut microbiota.
Joined by Lactobacillus GG
Lichtenstein originally came to Finland because of a discovery made by her husband, Professor Barry Goldin, and Professor Sherwood Gorbach. They had identified a gut-friendly bacterial strain named Lactobacillus GG, named after their surname initials, and started collaboration with the Finnish dairy company Valio. LGG was later commercialised by Valio in dairy products under the Gefilus brand name.
After she joined in for the visits, Lichtenstein was soon invited to give talks in her own field of expertise and to collaborate with Finnish researchers. “Professor Matti Uusitupa asked me to come and give lectures in Kuopio, and it became a yearly thing. “
She also hosted post doc researchers from Kuopio in her lab: Ursula Schwab, who is now Professor of Nutrition Therapy, and Arja Lyytinen, now Senior University Lecturer at UEF’s Institute of Public Health and Clinical Nutrition.
She finds teaching at a Finnish university somewhat different from the US. “Students in Finland are quieter and don’t ask many questions, and this hasn’t changed over the years although the proportion of international students has increased. They also tend to be very attentive and take their assignments seriously.”
Lichtenstein says she feels very fortunate to have such a long-term connection to Finland, both academically and personally. “I have made friends here and seen their children grow up. My own children also used to come along when they were young. Kuopio is a beautiful city that seems to have doubled in size over the years, but it’s still easy to walk everywhere, and I like wandering around downtown and especially in the harbour.
“There are also certain things I always like to bring back from Finland. I already have more Finnish glass than I can use, and everyone is always happy to get some Finnish chocolate.”
