Understanding the Gut-Body Clock Connection

Are you familiar with your circadian rhythm? Better known as your internal body clock it describes the biological patterns your body follows over a 24-hour period. It’s why we feel naturally more alert or sleepy at certain times, and why jet lag is so lousy! These rhythms affect every cell in your body – including your digestive tract and gut microbiome. Let’s delve further into the gut-body clock connection and discover how best to support it.

How do body clocks affect digestion? 

Circadian rhythms are set by the master clock deep in the brain, called the suprachiasmatic nucleus (SCN). This cluster of cells acts as the central timekeeper for our daily rhythms and responds to changes in light detected by the optic nerve in the eyes. 

The SCN synchronizes with thousands of smaller clocks located in peripheral tissues, including the gut. These clocks pick up external cues from things like light, temperature, and food.

In the digestive system, the body clocks regulate 24-hour patterns of:

• Gene expression

• Secretion of gastric acid and digestive enzymes

• Motility and bowel movements

In turn, food and meal timing – aka chrono-nutrition - influences the body clocks [1].  

Circadian rhythms are easily affected by long journeys across different time zones, shift work (especially night shifts), and eating at irregular times. In the digestive system these disruptions can affect digestion, nutrient absorption, motility, gut barrier function, immune health, and the balance and activity of the gut microbiome [2].

Circadian rhythms and the gut microbiome

Not only are these cellular timekeepers influencing gut activity, but research also shows there’s a two-way, 24-hour conversation happening between gut bacteria and our body clocks.

This daily rhythm plays out in the cyclical fluctuations in gut microbiome composition and function [1], and the fluctuations in the mucous layer lining the gut which gets thicker while we sleep [3].  

The colonizing effect of our gut microbiome changes too, with up to 10 times more bacteria to be found in the gut lining when we’re awake and active compared to when we sleep [3].  

What does this mean for health?

There’s still so much to unravel about the complex interplay between the gut microbiome and circadian rhythms but we do know that long-term disruption of this dynamic relationship can increase the risk of cardiovascular disease, cancer, depression, and inflammatory bowel disease [1].

Working with, rather than against, your body’s natural 24-hour rhythms is one of the best ways to support healthy microbial activity in the gut and normal immune function.

How do you find your body’s natural circadian rhythm?

Try these tips to get in tune with your natural rhythms:

• Keep to a regular bedtime and wake-up routine. Late nights and lie-ins are appealing, but if they become a regular habit, they disrupt your circadian rhythm. Instead, aim to have a regular bedtime and getting up time.

• Get outdoors in natural daylight as soon as possible after waking up. When your optic nerves register bright morning light, your brain is better able to detect the change in light at dusk. The fall in light levels stimulates melatonin production which helps you wind down in the evening, ready for sleep.

• Enjoy regular mealtimes. The timing of meals (known as chrono-nutrition) influences the body clocks in your gut and gut microbial activity. Aim to stick to a regular meal pattern and don’t eat just before bed.

• Nurture a healthy, diverse gut microbiome. Gut microbes love to feed on fibre from foods like oats, nuts, pulses, and vegetables, alongside polyphenols – the compounds that give fruits and vegetables their bright colours. Fibre helps the gut bacteria produce important signalling molecules like short-chain fatty acids and bile acids, while polyphenols interact with the gut microbiome and affect the expression of the central and peripheral circadian clock genes [4].

Establishing these patterns helps your body work in harmony with its natural rhythms and enjoy better digestion, energy, and sleep.

FAQs

What is a circadian rhythm? 

Your circadian rhythms are the natural biological patterns your body follows over a 24-hour period. These rhythms influence everything from wakefulness and sleepiness to energy levels, digestion, and the activity of your gut microbiome. 

The circadian rhythm is set by a “master clock” in the brain which works in tandem with smaller clocks in organs and tissues all over your body. Circadian rhythms are easily affected by long distance travel, shift work, and irregular mealtimes.

What’s the link between my circadian rhythm and gut health?

There’s a dynamic conversation between the body clocks in your gut and your gut microbiome. Food choices and meal timing influence the body clocks [1], while body clocks regulate the 24-hour patterns of gene expression, gut motility, and secretion of stomach acid and digestive enzymes.

The gut microbiome displays rhythmic patterns of activity and composition [1], and there are day/night fluctuations in the thickness of the mucous layer lining the gut and the levels of bacteria colonizing the gut lining [3].

Does waking up at different times every day disrupt my gut health?

Yes, irregular wake-up times can impact your digestion and gut health.  Gut activity is influenced by your circadian rhythm which in turn is regulated by external cues from daylight, waking up times, and meal times. When these rhythms are disrupted, you may notice a knock-on effect on gut health.

How do I reset my circadian rhythm?

You can reset your circadian rhythm by focusing on regular sleep/wake times, regular meal patterns, getting outside into daylight as soon as possible after waking, and by nurturing your gut microbiome. 

We hope this article helps you understand the intricate links between your body clock and gut health.  If your digestive rhythms need a helping hand, check out our range of ethically produced, planet-friendly supplements, ranging from Prebiotic Restore to Advanced Biotic and Vegan Digestive Enzymes – all available in our online store today.

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