Human Gut Microbiome and Nutrition Symposium recap

Written by Jeanette Gehrig, Graduate Student, The Gordon Lab

The Human Gut Microbiome and Nutrition Symposium brought together a broad range of people – from basic scientists to public health researchers and clinicians, in academia, industry, and the nonprofit sector – to tackle the deep-rooted and complex problem of childhood undernutrition.

As a graduate student in the Gordon Lab studying the role of the gut microbiota in undernutrition, this symposium could not have been more relevant. Having done preclinical studies on the effects of complementary food ingredients on the gut microbiota and host phenotypes, I am thrilled to see the results of my and others’ research implemented in a proof-of-concept trial in Bangladesh, which has begun enrollment.

It was incredible to finally meet one of our longstanding collaborators, Tahmeed Ahmed, from the International Centre for Diarrheal Disease Research, Bangladesh (icddr,b), who is conducting the trial. During his presentation, Tahmeed focused the successes and challenges of icddr,b’s work in Mirpur, an urban slum of Dhaka, Bangladesh. Thanks to Tahmeed and collaborators, mortality has decreased with standardized treatments for severe acute malnutrition (SAM). However, chronic undernutrition remains a problem. Currently, there is no standard treatment for children with moderate undernutrition, but Tahmeed, Jeff and collaborators are looking to change that. The trial focuses on children in Mirpur with moderate acute malnutrition (MAM) and will test whether microbiota-directed complementary foods, or MDCFs, can increase the abundance of healthy, age-appropriate bacteria in the gut. The underlying hypothesis is that MDCFs can increase microbiota maturity, which will in turn improve growth outcomes.

The theme for the symposium centered on opportunities and challenges in treating childhood undernutrition. Ralph Jerome from Mars, Inc. summarized the immensity of this challenge when he stated that with the world’s population over 7 billion people, 2 billion people are overweight, while 2 billion people suffer from undernutrition or micronutrient deficiencies. During the symposium lunch with the speakers, Tahmeed said that the root of undernutrition is inequality, but we can’t wait around until humanity achieves equality, so we do whatever we can in the meantime. So with a great challenge comes opportunity.

It was interesting to hear how the speakers and their collaborators were trying to better understand undernutrition and its causes and effects in order to improve treatment and outcomes. Ana María Arbeláez and Manu Goyal discussed how to better understand and prevent a tragic long-term effect of childhood undernutrition: reduced cognitive function. They emphasized the important observation that while brain size increases mainly before birth and during the first two years of life (“the first 1000 days”), markers of brain development like blood flow and glucose uptake peak between 3 to 5 years of age. Ana and Manu are using neuroimaging to better understand the developing brain and what happens in cases of undernutrition. Is the brain vulnerable to undernutrition, or does the body try to spare the brain at all costs?

Lora Iannotti shared two recent success stories in Ecuador. In one trial, Lora and collaborators gave fortified peanut snacks to school-aged children with the primary outcome of reducing anemia. Disappointingly, the snack had no effect on anemia. After careful consideration, they repeated the trail, but dewormed the children in addition to providing the snack, and they were able to drastically reduce anemia. In a separate trial aiming to reduce stunting in infants, Lora and collaborators provided an egg a day for three months starting at six months of age. The treatment significantly improved anthropometric measures, including length-for-age Z score (LAZ), which historically has been the most difficult metric to improve since it reflects chronic undernutrition.

The importance of social and cultural sensitivity was a theme that permeated the symposium. Lora emphasized that success of the egg trial depended on a large social marketing campaign encouraging parents to give eggs to their young children. Eggs are traditionally consumed by children, but not as early as six months. Fil Randazzo from the Bill and Melinda Gates Foundation described the Foundation’s emphasis on ESC, or Ethical, Social, and Cultural Support. You may have the most efficacious treatment for undernutrition, but if parents are not willing to give it to their children, it is useless. Successful long-term treatments for undernutrition should not only be culturally acceptable and affordable, but should empower local communities.

Overall, the Human Gut Microbiome and Nutrition Symposium helped me see the broad context of my research. It emphasized the deep-rooted, complex nature of the problem that requires thoughtful, deep-rooted solutions. In the face of such a tremendous challenge, it was encouraging to see so many people working together, from academia, industry, and nonprofits, making real progress on better understanding and treating undernutrition.

Slides and Videos

Dr. David D’Argenio

Dr. Manu Goyal

Dr. Ana Maria Arbelaez

Dr. Lora Iannotti

Dr. Subhasish Das