The study was published in the latest issue of the Journal of Immunology.
Scientists at Augusta University have some of the first evidence of how the cheap, over-the-counter antacid can encourage our spleen to promote an anti-inflammatory environment that could be therapeutic in the face of inflammatory disease.
They have shown that when rats or healthy people drink a solution of baking soda, or sodium bicarbonate, it becomes a trigger for mesothelial cells sitting on the spleen to tell the fist-sized organ that there’s no need to mount a protective immune response.
“It’s most likely a hamburger not a bacterial infection,” is basically the message, said Paul O’Connor, a renal physiologist at Augusta University and the study’s corresponding author.
According to the researchers, mesothelial cells line body cavities, like the one that contains our digestive tract.
It was found that these cells had little fingers, called microvilli, which could sense the environment, and warn the organs they have covered that there is an invader and an immune response is needed.
They said drinking baking soda told the spleen, a part of the immune system that acts like a big blood filter and is where some white blood cells, like macrophages, are stored, to go easy on the immune response.
The conversation, which occurs with the help of the chemical messenger acetylcholine, appears to promote a landscape that shifts against inflammation, they said.
In the spleen, as well as the blood and kidneys, the researchers found after drinking water with baking soda for two weeks, the population of immune cells called macrophages, shifted from primarily those that promote inflammation, called M1, to those that reduce it, called M2.
Macrophages, best known for their ability to consume garbage in the body like debris from injured or dead cells, are early arrivers to a call for an immune response.
The researchers also saw a shift in other immune cell types, like more regulatory T cells, which generally drive down the immune response and help keep the immune system from attacking our own tissues.
That anti-inflammatory shift was sustained for at least four hours in humans and three days in rats.
The study has shown that the shift ties back to the mesothelial cells and their conversations with our spleen with the help of acetylcholine.
“We think the cholinergic signals that we know mediate this anti-inflammatory response aren’t coming directly from the vagal nerve innervating the spleen, but from the mesothelial cells that form these connections to the spleen,” O’Connor said.
When they cut the vagal nerve, a big cranial nerve that starts in the brain and reaches into the heart, lungs and gut to help control things like a constant heart rate and food digestion, it did not impact the mesothelial cells’ neuron-like behavior.
But when they removed or even just moved the spleen, it broke the fragile mesothelial connections and the anti-inflammatory response was lost, O’Connor said.
“You are not really turning anything off or on, you are just pushing it toward one side by giving an anti-inflammatory stimulus,” he said, in this case, away from harmful inflammation.
“It’s potentially a really safe way to treat inflammatory disease.”
Also, the spleen got bigger with consuming baking soda, and the scientists think this is because of the anti-inflammatory stimulus it produces.