Guess what artichokes, asparagus, bananas, garlic, onions, tomatoes and whole wheat all have in common to keep your body at a healthy weight? The answer: These six foods contain short-chain fructo-oligosaccharides (FOS), which promote the growth of healthy intestinal bacteria.
Beyond vitamins, minerals and phyto-nutrients, the foods we eat also feed the bacteria in the digestive tract. These bacterial communities are also known as our gut microbiome. Certain types of fibers and carbohydrates, or saccharides, in fruits and vegetables are pre-biotics that foster the growth of healthy bacterial communities. And that takes us back to our answer above: particular carbohydrates like short-chain fructo-oligosaccharides (FOS) can shift the balance towards a healthy microbiome, whereas foods rich in fats select for bacterial communities that may not be good for your overall health.
Dena Herman (Associate Professor, Family and Consumer Sciences) is finding out more about the relationship between diet and the composition of the gut microbiome. More specifically, Herman and her collaborator Gilberto Flores (Assistant Professor, Biology) are studying how the dietary habits of children influence the composition of their gut microbiomes. Herman received funding to do this research through the Suzan Jean Lebowitz 2014-15 Research Support Grant Competition for Faculty Research in Nutrition Sciences.
The project is called, Childhood Obesity and the Gut Microbiome: What do We Know? Herman and Flores are working together to characterize the composition of the gut microbiome in 100 children using samples collected over three days over the course of two months. Detailed dietary data was also collected for the 24-hour period prior to microbiome sampling.
“We anticipate, based on whether a child is overweight or appropriate weight, that we will see a marked variation in which bacterial families are dominant. Fecal samples will show what each child’s microbial community looks like and we’ll examine whether, and how, different dietary patterns affect these bacterial communities,” Herman said. “We anticipate that more fruits, vegetables and high-fiber will bring about more ‘good’ bacteria and healthy weight.”
The study will also take into consideration access to healthy food and the amount of time children spend in front of television or video/computer screens (screen time). “This pilot study also hopes to determine the role sedentary activities play in eating behaviors and food choices and whether there is a relationship between these and the types of bacteria that are dominant in the gut of children."
The research team will involve undergraduate and graduate students studying Nutrition and Biology who will study whether, and to what extent, a propensity toward obesity can be determined by a predominance of one or another type of intestinal bacteria and how this relates to diet.
“I like the idea of engaging undergraduate students in research that is usually reserved for graduate students,” Herman said. “They will learn about dietary intake, how to collect data, and how to do data analysis.” The students will be selected from the Medical Nutrition Therapy and Community Assessment course Herman teaches in the Department of Family and Consumer Sciences. “Some of the undergraduates who were in my community nutrition program last semester are getting to be experts already and are excited about progressing in their academic careers,” she said.
“The subjects’ parents also have a lot of work to do,” Herman said, “We’re asking them to write down everything their children eat. I mean everything. If it’s a sandwich, what kind of mayo was on it – what brand—how much–so we can look up the ingredients. Every ingredient is important. We’ll enter all the information into the computer for analysis to understand macro- and micro-nutrients.”
“This is pretty cutting
edge stuff,” Herman said. “And it’s a great opportunity for our students. The Biology students will be processing the samples and the Nutrition students will have the opportunity to observe these processes, which include DNA extraction, amplification, and sequencing. This aspect of the project is being performed in Dr. Flores’ microbiology lab. It’s a great example of interdisciplinary research and collaboration across the CSUN campus.”
Herman likes getting undergraduates involved in this type of research because it creates a natural pathway into their professions. “It gets them excited and forward thinking about their careers,” she said.
“We talk a lot about service learning and this is so hands on. One student came up to me after a session in the lab and told me that the idea of a graduate thesis had seemed too daunting, so graduate school wasn’t on the table, but after getting involved in actual research and data collection she could take ownership of a project. Understanding the process from start to finish generated excitement.”
Herman says she has been interested in nutrition as far back as she can remember. “My grandfather was a physician who died of complications of diabetes. My father became a personal chef and also developed diabetes. I suppose the awareness of the health problems that might be avoided through good nutrition had me interested from an early age. In kindergarten I ate carrots, not cookies. I was that kid,” she said. Trained as a pediatric dietitian, she finds nothing more powerful than nutrition to help children reach developmental milestones.
Jean O'Sullivan
F2014