Dr Partha Nandi is a gastroenterologist who wants you to know that the key to preventing stroke, Alzheimer’s and Parkinson’s might not lie in the brain at all – it lies in the gut. In this episode of Age Better, he shares how inflammation in your gut today could be affecting your brain decades from now. And he reveals the five simple pillars that could help you protect your cognitive health for life.
How inflammatory markers in the gut can predict our risk of Parkinson’s
We usually think of Parkinson’s disease as a neurological condition, defined by tremors, stiffness and changes in movement. But according to Dr Partha Nandi the earliest signs of the disease may actually appear in the gut.
“You can see changes of Parkinson’s in the gut prior to the time,” he says. “Often a decade or more earlier, before anyone has symptoms.”
The gut-brain axis explained
The gut and brain are in constant communication via the vagus nerve, forming what’s called the gut-brain axis. Along this pathway sits the gut microbiome. This is a vast ecosystem of bacteria, viruses and fungi that plays a key role in various processes, including immunity and inflammation.
“The gut and the brain are intimately connected,” explains Dr Nandi. “They communicate because they need one another.”
One crucial feature is the gut lining itself. It’s only one cell thick, protected by a thin layer of mucus. When that barrier becomes compromised (a process known as increased intestinal permeability) inflammatory particles can escape into the bloodstream.
“That’s the beginning of gut inflammation,” says Dr Nandi. “And when inflammation begins in the gut and travels into your bloodstream, it can break the blood-brain barrier and cause inflammation in the brain.”
Early inflammatory markers and Parkinson’s
In Parkinson’s disease, the brain contains characteristic inflammatory structures known as Lewy bodies. Research shows that these same hallmarks can be detected in the gut years before symptoms develop.
This goes some way to explaining why digestive symptoms such as constipation frequently precede Parkinson’s.
“It’s not that constipation means you have Parkinson’s,” reassures Dr Nandi. “It’s that the gut may be giving you a signal that something isn’t right.”
While Parkinson’s is multifactorial, chronic gut inflammation appears to be a significant piece of the puzzle.
“If we could prevent that inflammation a decade or two earlier, then you could possibly decrease the presence of this disease in the brain,” says Dr Nandi.
Why inflammation matters
Inflammation itself is not harmful. It’s a normal immune response. Problems can arise, however, when it becomes chronic.
Processed foods, excess sugar, poor-quality fats, chronic stress and lack of movement all disrupt the gut microbiome. Over time, this imbalance promotes ongoing inflammation.
“Your gut has the most sophisticated immune system in your body,” says Dr Nandi. “When small particles cross that gut barrier repeatedly, the immune system is constantly activated, and that inflammation doesn’t stay local.”
And science is starting to back this up too. Research shows that altering the gut microbiome can influence neurological outcomes after stroke, and potentially neurodegenerative disease more broadly.
Can we act before symptoms appear?
As Dr Nandi explains, a few lifestyle tweaks can go a long way in reducing gut inflammation.
“To me, the most powerful weapon you have against disease is your fork,” says. “If you pay attention to what you’re eating, you actually change the composition of your gut microbiome.
“You’re not just a passive passenger on this ride. You can change things.”
Whole foods that are rich in fibre help to feed beneficial bacteria. Fermented foods, such as yoghurt, kefir, kimchi and sauerkraut also support a healthier gut environment.
One thing that’s often not talked about, however, is movement.
“When you have movement, you actually change the components of your gut microbiome and decrease dysbiosis,” Dr Nandi explains.
Stress management, purpose and community matter too. Chronic stress raises cortisol levels, which are closely linked to gut permeability and inflammation. “When you decrease stress you decrease inflammation,” says Dr Nandi. “And that directly affects gut health.”
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