Stress damages the gut health of poultry by weakening the gut barrier, disrupting the microbiota, and triggering inflammatory processes. This increases the risk of infections, poorer feed utilization, and reduced productivity. In this article, we answer the most frequently asked questions about how stress affects the gut of chickens and what you can do about it.
What happens in the gut of poultry during stress?
During stress, a chicken’s body responds with a cascade of physiological changes that directly affect the gut. The gut barrier weakens, blood flow decreases, and the production of protective mucus declines. The result is increased permeability of the intestinal wall, also known as “leaky gut,” allowing harmful bacteria and toxins to more easily enter the bloodstream.
The intestinal wall of poultry consists of a layer of epithelial cells held together by so-called tight junction proteins, such as occludin and claudin-1. Under stress conditions, the expression of these proteins decreases, weakening the barrier function. This is not a temporary inconvenience: prolonged stress leads to structural damage to the intestinal villi. Villus height decreases and crypt depth increases, which reduces the absorption surface and impairs nutrient utilization.
At the same time, stress hormones such as corticosteroids activate inflammatory responses in the intestinal wall itself. This amplifies the damage and makes the animal more susceptible to secondary infections by pathogens such as E. coli, Salmonella, and coccidia.
Which stressors damage gut health the most?
The stressors that place the greatest burden on the gut health of poultry are heat stress, infectious challenges, nutritional fluctuations, and management stress such as relocation or vaccination. Heat stress stands out as one of the most common and underestimated causes of gut damage, especially in warm climates or during summer periods.
During heat stress, the body redirects blood away from the intestines toward the skin to dissipate heat. This reduces the oxygen supply to the intestinal epithelium, causing cell death and loss of barrier function. Research shows that heat stress significantly increases oxidative stress in intestinal cells, further amplifying the damage.
Other important stressors include:
- Infections and coccidiosis: Coccidia directly damage the intestinal epithelium and disrupt osmoregulation in intestinal cells.
- Dietary changes: Abrupt diet switches disrupt the microbiota and lower the pH buffer in the gut.
- Relocation and social stress: Elevated corticosteroid levels during transport or flock changes inhibit gut function.
- Antibiotic use or withdrawal: Especially in a No Antibiotic Ever strategy, animals are more vulnerable to dysbiosis without additional support.
How does stress disrupt the gut flora of chickens?
Stress disrupts the gut flora of chickens by shifting the balance between beneficial and harmful bacteria toward dysbiosis. Under stress conditions, the number of pathogenic bacteria such as Clostridium perfringens and E. coli increases, while populations of protective bacteria such as Lactobacillus species decline.
A healthy gut flora, also called eubiosis, is essential for a well-functioning gut barrier, efficient digestion, and a strong immune system. When stress destabilizes the microbiota, this has direct consequences for the production of short-chain fatty acids such as butyrate, which intestinal cells use as an energy source and which support gut integrity.
Dysbiosis also leads to fermentation problems in the gut, causing wet litter and poor litter quality. This in turn increases the risk of footpad lesions, skin irritations, and secondary infections, creating a negative spiral that puts significant pressure on technical performance.
For a healthy microbiota, a stable environment is crucial. Products that regulate the pH in the gastrointestinal tract and inhibit the growth of harmful bacteria play a supportive role in this. You can read more about this approach on our page about drinking water and feed additives.
Why are young and producing animals particularly vulnerable?
Young chicks and producing laying hens are particularly vulnerable to stress-related gut damage because their gut barrier is not yet fully developed or is placed under additional strain by the high physiological demands of production. In chicks, the gut flora is still unstable and susceptible to disruption during the first weeks of life. In laying hens in the mid- and late-laying phase, the resilience of the gut gradually decreases.
In young chicks, the intestinal epithelium is particularly vulnerable during the first three weeks. The tight junctions are not yet fully formed and the microbiota is still being established. Any stressor during this phase, whether heat, vaccination, or a pathogen, can permanently disrupt gut development and negatively affect growth performance for the remainder of the flock cycle.
Laying hens in the productive phase face a different challenge. The high metabolic burden of egg production diverts much energy and nutrients away from maintenance processes, including gut integrity. Heat stress during this phase leads not only to gut damage, but also to reduced shell strength, lower egg production, and shorter laying persistence.
How can betaine support gut health under stress?
Betaine supports the gut health of poultry under stress through four mechanisms: it strengthens the gut barrier, reduces oxidative stress and inflammation, improves villus structure, and promotes a healthy microbiota. This makes betaine one of the most versatile natural ingredients for gut support in poultry.
As a compatible osmolyte, betaine protects intestinal cells against dehydration and osmotic stress during heat. It moves from the extracellular fluid into the cytosol, attracts water molecules, and stabilizes proteins. This reduces the energy requirement for osmoregulation via ion pumps and keeps cell function intact, even at elevated ambient temperatures.
Betaine also increases the expression of tight junction proteins such as occludin and claudin-1, literally strengthening the gut barrier. Studies using the TEER model, a measure of gut barrier function in vitro, show that natural betaine delivers significantly better results than synthetic variants. Intestinal cells supported with natural betaine exhibit stronger tight junctions and better resistance to infections. You can find more information about how betaine works on our betaine information page.
In addition, betaine improves villus height and reduces crypt depth, leading to a larger absorption surface and better nutrient utilization. This is reflected in improved feed conversion ratios and higher growth rates, even under stress conditions.
How Jodoco helps with gut health in poultry under stress
At Jodoco, we develop products that actively support the gut health of poultry, even when stress conditions increase the pressure. Our scientifically substantiated portfolio combines natural ingredients such as betaine, organic acids, medium-chain fatty acids, and essential oils for a broad and effective approach.
Our products offer concrete benefits for poultry farmers dealing with heat stress, infectious pressure, or a No Antibiotic Ever strategy:
- Jodobet: Natural betaine as an osmolyte and methyl donor. Strengthens tight junctions, improves villus structure, and protects cells against heat stress. Proven effective in broilers and laying hens.
- Jodoplume: Combination of natural betaine, organic acids, and copper for drinking water application. Supports gut health and lowers the pH in the gastrointestinal tract to inhibit pathogens such as E. coli and Salmonella. More information can be found on the Jodoplume product page.
- Grovax: Liquid source of organic acids, slow-release butyrate, medium-chain fatty acids, and essential oils. Strengthens gut integrity, combats gram-negative and gram-positive bacteria, and fits perfectly into an antibiotic-free strategy.
Whether you are dealing with heat stress during the summer months, an outbreak of coccidiosis, or a vulnerable flock of young chicks: we are happy to think along with you about the most effective approach. Contact us and discover which solution best suits your situation.
