Sci Adv: Organ-like studies reveal the effects of the digestive system on neurological disorders

January 30, 2021 /--- In many ways, our brains are closely linked to the digestive tract: feeling nervous can cause stomach pain, and signs of hunger in the gut can make us irritable.
recent studies have even shown that bacteria living in our guts can affect certain neurological diseases.
it is difficult to model these complex interactions in animals, such as mice, because their physiology is very different from that of humans.
to help researchers better understand the intestinal axis, researchers at the Massachusetts Institute of Technology have developed a "chip organ" system that replicates the interactions between the brain, liver and colon.
the system, researchers were able to simulate the effects of microbes living in the gut on tissue samples from healthy brain tissue and People with Parkinson's disease.
found that short-chain fatty acids produced by microbes in the gut are transported to the brain, with different effects on health and diseased brain cells.
Martin Trapecar, a postdoctoral student at the Massachusetts Institute of Technology, said: "While short-chain fatty acids are largely beneficial to human health, we have observed that under certain conditions they further exacerbate certain parkinson's disease-related brain diseases, such as protein misfolding and neuron death.
lead author of the study.
lead author of the paper is Linda Griffith, a professor of bioengineering and mechanical engineering, and the results were recently published in the journal Science Advance.
recent years, Griffith's lab has been developing microphysiological systems that can be used to grow engineering tissue models of different organs connected by microflow channels.
, these models can provide more accurate information about human diseases than animal models, said Griffith, a director of the University of Human Rights.
paper published last year, the authors used a microphysiological system to simulate the interaction between the liver and colon.
study, they found that molecular short-chain fatty acids (SCFA) produced by microbes in the gut can in some cases exacerbate autoimmune inflammation associated with ulcerative colitis.
SCFA, including butylate, propylate and acetate, can also have beneficial effects on tissues, including enhanced immune tolerance.
(Photo Source: www.pixabay.com) In the new study, the MIT team decided to add brains and circulating immune cells to their multi-organ systems.
, they worked with Jaenisch Labs at the Whitehead Institute.
Jaenisch has previously developed a way to convert fibroblasts from People with Parkinson's disease into ergonomic stem cells, which can then be induced to differentiate into different types of brain cells - neurons, asstary glial cells and small glial cells.
researchers at the Massachusetts Institute of Technology used cells in the Parkinson's model to carry a mutation that causes a protein called α synactin to accumulate, damaging neurons and causing inflammation of brain cells.
Jaenisch's lab also produced brain cells that had corrected the mutation.
Griffith and Trapecar first studied these two groups of brain cells in the microphysiological system, and the corrected cells showed more inflammation.
the lipids and cholesterol metabolism of Parkinson's cells were also relatively impaired.
, the researchers built a channel through which immune cells and nutrients, including SCFA, flow between them, connecting brain cells to colon and liver tissue.
found that exposure to SCFA is beneficial for healthy brain cells and helps them mature.
, when brain cells in people with Parkinson's disease are exposed to SCFA, their beneficial effects disappear.
, cells experience higher levels of protein misfolding and cell death.
these effects can be seen even if immune cells are removed from the system, leading researchers to assume that these effects are mediated by changes in lipid metabolism.
seems to affect neurodegenerative diseases by affecting lipid metabolism rather than directly affecting certain immune cell groups," said Trapecar, an immune group.
" (Bioon .com) Source: 'Organs-on-a-chip' system sheds light on how bacteria in the human digestivetract may influence neurological diseases information link: "Human hysiomimetic model integrating microphysics systems of the gut, liver and brain for studies of neurodegenerative diseases" advances.sciencemag.org/lookup 1126/sciadv.abd1707