Choosing the right adjusted fiber diet for your animal model study

Researchers are often interested in the effects of fiber in their laboratory animal diet. As an example, the recent focus on the brain-gut connection in neurodegenerative conditions like Parkinson’s disease requires a greater understanding of how fiber content in diets can have an impact on brain health. However, defining and measuring dietary fiber has always been challenging. Derek Martin, PhD, RD, a nutritionist at Envigo explained:

“The broad definition of fiber is the carbohydrate components that are resistant to digestion in the upper gastrointestinal tract by mammalian enzymes. However, various organizations define fiber differently, which not only creates issues around food labeling, but also makes it difficult for researchers to know if the diet they have chosen for the animals in their study is truly representing the fiber content they were aiming for.”

Below, Derek talks in more detail about the importance of fiber in research animal diets.

What is the importance of dietary fiber for health?

Technically, humans don't need dietary fiber to survive, but it does seem to have many health benefits. As Derek described:

“Populations that consume more fiber generally have lower incidences of chronic diseases, especially those that are prevalent in Western societies. However, there hasn’t been much research on this from an animal nutrition standpoint. That said, we know that animals fed on low-fiber diets will experience health issues more frequently than those with adequate fiber in their diets.”

What areas of research typically require or benefit from high-fiber diets?

Typically, researchers are interested in how fiber interacts with the medical condition they are investigating. They may also want to learn about whether the therapeutic approach they are developing is affected by a high or low fiber diet. Derek continued:

“Inflammatory bowel disease is a good example of a research area in which it is important to monitor and control the amount of fiber in animal diets. Other researchers may want to add fiber to high-fat diets to understand more about the affect of fiber on a calorically dense diet, and how that might interact with conditions like obesity.”

In addition, manipulating fiber in animal diets can help us understand more about the gut-brain axis:

“There has been a lot of research recently on the impact of fiber on neurodegenerative conditions. It’s become increasingly important to understand how fiber in the diet affects the brain, with new opportunities for preventative therapies that manipulate the microbiome to improve brain health.”

How are high fiber diets created and developed?

Derek works closely with researchers to achieve the experimental manipulations they need to test their research questions. He often consults closely with scientific teams to help them to gain a fuller understanding of the diets that are used in their fields. Importantly, the literature often reports that animals were fed on no-fiber or low-fiber diets, but due to inconsistencies in how fiber is defined, this can sometimes be inaccurate. Derek talked us through the Envigo approach:

“Typically, researchers will want to use a low-fiber diet as a control, and add a source of fiber to that same diet. If they are interested in gut health for example, they might then want to compare the impact of those two diets on the gut microbial environment. I will usually work with a research team to get an understanding of the type and amounts of fiber they need in order to answer their research questions more precisely, and advise them accordingly.”

There are additional practical issues to consider when choosing diets, and researchers can benefit from speaking with nutritionists to help them take these into account when designing their study. Derek explained:

“We are able to share knowledge with research teams to help them understand what to expect when working with certain types of diets. This can include knowing whether a diet is likely to cause animals to experience gastrointestinal upset, or when a diet is formulated in a way that makes it impossible to deliver in pellet form. These are some of the ways we can help researchers to mitigate potential problems before their experiment gets underway.”

At Envigo, our dedicated and experienced nutrition team work closely with our customers in developing diets for certain weights, ages, or following a set program for diet maintenance. Our nutritionists are available to answer any questions you may have about your project plans.