Fiber and Gut Health Podcast

Interested in learning more about fiber and gut health? Check out a recent podcast on the Radio Health Journal that I contributed to:

Fiber is an important part of a daily diet, but many people do not know what fiber  does for the body. Dr. Hannah Holscher, Assistant Professor of Nutrition at the University of Illinois-Urbana-Champaign, explains that fiber is a non-digestible carbohydrate that is found in plants which human enzymes cannot break down, so the body relies on microbes.

Exercise Alters Our Microbiome. Is That One Reason It’s So Good for Us?

Exercise Alters Our Microbiome.  Is That One Reason It’s So Good for Us?

New York Times

By Gretchen Reynolds

Exercise may change the composition and activity of the trillions of microbes in our guts in ways that could improve our health and metabolisms over time, a new study finds.

Click on the picture above to check out the full story on our research that’s featured in a January 3, 2018 article in the New York Times.

Interested in reading our final published manuscript?  You can find that here:

Allen JM, Mailing LJ, Niemiro GM, Moore R, Cook MD, White BA, Holscher HD, Woods JA. Exercise-induced shifts in the gut microbiome and associated metabolites are dependent on obesity status. Medicine & Science in Sports & Exercise. 2017. DOI: 10.1249/MSS.0000000000001495

Fiber Is Good for You. Now Scientists May Know Why.

By Carl Zimmer, New York Times

Click on the picture to read the full story in the New York Times.

A diet of fiber-rich foods, such as fruits and vegetables, reduces the risk of developing diabetesheart disease and arthritis. Indeed, the evidence for fiber’s benefits extends beyond any particular ailment: People who eat more of it simply have lower odds of dying.

Hannah D. Holscher, a nutrition scientist at the University of Illinois who was not involved in the new studies, said that the results on mice need to be put to the test in humans. But it’s much harder to run such studies on people.

In her own lab, Dr. Holscher acts as a round-the-clock personal chef. She and her colleagues provide volunteers with all their meals for two weeks. She can then give some of her volunteers an extra source of fiber — such as walnuts — and look for changes in both their microbiome and their levels of inflammation.

Dr. Holscher and other researchers hope that they will learn enough about how fiber influences the microbiome to use it as a way to treat disorders. Lowering inflammation with fiber may also help in the treatment of immune disorders such as inflammatory bowel disease.

Fiber may also help reverse obesity. Last month in the American Journal of Clinical Nutrition, Dr. Holscher and her colleagues reviewed a number of trials in which fiber was used to treat obesity. They found that fiber supplements helped obese people to lose about five pounds, on average.

Click on the picture above to read the full story in the January 1, 2018 Science & Heath Sections of the New York Times.

Holscher receives prestigious Foundation for Food and Agriculture Research Award for early-career innovation in nutrition

Holscher receives prestigious Foundation for Food and Agriculture Research Award for early-career innovation in nutrition

URBANA, Ill. – Hannah Holscher, assistant professor of nutrition in the Department of Food Science and Human Nutrition at the University of Illinois is a recipient of the second annual New Innovator in Food and Agriculture Research award. The annual set of early-career grants to outstanding food and agriculture research faculty members is a program of the Foundation for Food and Agriculture Research (FFAR), a nonprofit established through bipartisan congressional support in the 2014 Farm Bill.

Holscher received a FFAR grant of nearly $600,000 to fund a project looking at diet, the human gastrointestinal microbiome, and metabolic health over the next three years. Research in Holscher’s laboratory at U of I, the Nutrition and Human Microbiome Laboratory, integrates the areas of nutrition, gastrointestinal physiology, and the microbiome. Her research focuses on the clinical application of nutritional sciences with an overarching goal of improving human health through dietary modulation of the gastrointestinal microbiome.

“The results of my research will provide information that will help consumers to make healthful food choices,” Holscher explains. “It will also inform dietary guidance given by registered dietitians, health care providers, and extension specialists. The findings will be applicable to food consumption, food and nutrition practice, and human health outcomes.”

“The Foundation for Food and Agriculture Research is pleased to support Dr. Holscher’s research as part of our work to catalyze innovation and foster a strong scientific workforce for the future,” says Sally Rockey, executive director of FFAR. “I look forward to seeing the impact of the New Innovator in Food and Agriculture Research award not only on Dr. Holscher’s career, but also on advancing agriculture.”

The New Innovator in Food and Agriculture Research program supports promising scientists who demonstrate not only a commitment to catalyzing innovation in food and agriculture, but also a dedication to mentoring students.

Holscher joins a group of other 2017 New Innovator in Food and Agriculture Research award recipients who were selected from across the United States in five categories: nutrition and healthy food choices; plant efficiency; optimizing agricultural water use; spurring food system innovation; and transforming soil health.

The second annual set of New Innovator awards brings the total FFAR investment in the program to more than $4.5 million. Learn more about the 2017 New Innovators and their research directions.


Study explores how composition and function of gut microbiota changes during day

Study explores how composition and function of gut microbiota changes during day

By Stephen Daniells in NUTRA


The composition and function of the microbiota in the human gut changes throughout the day, with links to dietary and bathroom habits. The findings may have implications for the design of future probiotic clinical trials.

See the newsletter and our publication  “Time of day and eating behaviors are associated with the composition and function of the human gastrointestinal microbiota” in the American Journal of Clinical Nutrition to learn more.

Nourish Your Gut Microbiota

Nourish Your Microbiota

A publication from Tufts Health and Nutrition Letter & the Huffington Post

06/16/2017 03:34 pm ET Updated Jun 18, 2017

Eating a diverse, plant-rich diet helps fuel the growth of beneficial bacteria.

Microbes ― bacteria and other tiny critters not visible to the naked eye but numbering in the trillions ― are busy in your body. Many of these microbes benefit you. Others have the potential to cause harm. This community of microbes is called the microbiota. Their genes are called the microbiome.

Studies of cross-sections of people across the world suggest the more fiber you consume – especially if from a wide range of plant foods – the more diverse your gut microbiota will be. Additionally, intervention studies in people have shown that consuming more fiber and whole grains increases diversity of gut bacteria.

Different microbes are capable of breaking down (fermenting) different fibers. Holscher explains that it takes different enzymes to break down the various fibers found in foods. Some bacteria have many different enzymes, so they can utilize dozens of different fibers. Other bacteria may only be able to break down one or a few different fibers. By eating a variety of plant foods with different types of fibers, you may encourage the growth of a more diverse population of beneficial microbes capable of breaking down those fibers.

See the article in the Huffington Post to learn more. 

Microbes and Gut Health: Meet Some Tiny Friends

What’s a microbiome and why should I care?
How do microbes help keep us healthy?
What’s the difference between prebiotics and probiotics anyway?
Does the microbiome change as we age?
Join us on Thursday, August 4, from noon to 1 p.m. as Dr. Hannah Holscher, assistant professor in the Department of Food Science and Human Nutrition at the University of Illinois, discusses your questions about diet and the trillions of microbes that live inside of you during a one-hour chat on Twitter. Use the #askACES to ask your questions about the microbiome, how microbes keep us healthy, what foods we can eat to keep good microbes happy, and more!Missed the chat? Listen to the podcast below.

Agave Inulin Supplementation Affects the Fecal Microbiota of Healthy Adults Participating in a Randomized, Double-Blind, Placebo-Controlled, Crossover Trial


Background: Prebiotics resist digestion, providing fermentable substrates for select gastrointestinal bacteria associated with health and well-being. Agave inulin differs from other inulin type fibers in chemical structure and botanical origin. Preclinical animal research suggests these differences affect bacterial utilization and physiologic outcomes. Thus, research is needed to determine whether these effects translate to healthy adults.

Objective: We aimed to evaluate agave inulin utilization by the gastrointestinal microbiota by measuring fecal fermentative end products and bacterial taxa.

Methods: A randomized, double-blind, placebo-controlled, 3-period, crossover trial was undertaken in healthy adults (n = 29). Participants consumed 0, 5.0, or 7.5 g agave inulin/d for 21 d with 7-d washouts between periods. Participants recorded daily dietary intake; fecal samples were collected during days 16–20 of each period and were subjected to fermentative end product analysis and 16S Illumina sequencing.

Results: Fecal Actinobacteria and Bifidobacterium were enriched (P < 0.001) 3- and 4-fold after 5.0 and 7.5 g agave inulin/d, respectively, compared with control.Desulfovibrio were depleted 40% with agave inulin compared with control. Agave inulin tended (P < 0.07) to reduce fecal 4-methyphenol and pH. Bivariate correlations revealed a positive association between intakes of agave inulin (g/kcal) and Bifidobacterium (r = 0.41, P < 0.001). Total dietary fiber intake (total fiber plus 0, 5.0, or 7.5 g agave inulin/d) per kilocalorie was positively associated with fecal butyrate (r = 0.30, P = 0.005), tended to be positively associated withBifidobacterium (r = 0.19, P = 0.08), and was negatively correlated withDesulfovibrio abundance (r = −0.31, P = 0.004).

Conclusions: Agave inulin supplementation shifted the gastrointestinal microbiota composition and activity in healthy adults. Further investigation is warranted to determine whether the observed changes translate into health benefits in human populations. This trial was registered at as NCT01925560.