Building a Stronger Immune System

Managing bacteria and other microorganisms in the body, rather than just fighting them, may lead to better health and a stronger immune system, according to Eric Harvill, professor of microbiology and infectious disease.

“We are beginning to understand that the immune system interacts with far more beneficial bacteria than pathogens,” said Harvill. “We need to reenvision what the true immune system really is.”

This reinterpretation leads to a more flexible approach—balanced between defending against pathogens and enlisting the help of beneficial microbes—to understanding how the immune system interacts with microbes.

According to Harvill, the system that includes bacteria and other microbes in the human body, or the microbiome, is much larger and more integrated into human health than most people suspect. Adding to the complexity is the adaptive capacity of the human immune system. The immune system can develop antibodies against certain pathogens, which it can reuse when threatened by future attacks from the same pathogen.

Harvill, whose research is supported by the National Institute of General Medical Sciences and whose viewpoint appears in the latest issue of mBio, noted that some researchers have not yet accepted this broader approach to the immune system.

“Among immunologists or microbiologists, this is an alien concept,” said Harvill. “It’s not part of how we have historically looked at the immune system, but it’s a useful viewpoint.”

Other researchers who study plant and nonhuman biology are already starting to embrace the concept. For example, plant biologists are beginning to recognize that viruses can help plants resist drought and heat.

“Within nonhuman immunology, this is not an alien concept because they have seen many examples of beneficial relationships between the host and its microbial commensals,” Harvill said.

Harvill believes that adopting this new perspective could be the first step toward new medical treatments.

“This new viewpoint suggests new experiments and results will be published,” he said. “And, hopefully, the concept becomes more mainstream as supporting evidence accumulates.”

Matthew Swayne