Have you ever had to make an extremely difficult and psychologically painful decision under extreme pressure? Or have you ever felt anxiety so severe that it caused you stomach pain? If you have gone through one of these two experiences, you must be aware of the extent to which stress affects your digestive system, according to the Everyday Health website.
The brain and the intestine have a close relationship and continuous communication. Sensory nerves in the intestine transmit signals to the brain via the spinal cord and the vagus nerve.
“Stress can affect every part of the digestive system,” says Dr. Kenneth Koch, a professor of gastroenterology at Wake Forest University School of Medicine in Winston-Salem, North Carolina.
What happens in your gut when your body is stressed?
The connection between the brain and the gut is known as the brain-gut axis, which is a two-way communication network that connects the central nervous system, which consists of the brain and spinal cord, to the enteric nervous system, a complex network of between 200 and 600 million neurons found in the lining of the intestine.
The enteric nervous system regulates digestive system functions, including:
- Digestion process.
- Absorption of nutrients.
- Movement of food and waste through the intestine.
However, stress may greatly affect the way the body performs these processes.
When faced with a situation that may pose a threat, the sympathetic nervous system, which is part of the autonomic nervous system responsible for regulating vital body functions, such as heartbeat, breathing, and blood pressure, responds by activating the “fight or flight” response (fight or flight). This leads to the secretion of the stress hormone cortisol, which puts the body in a state of alert and readiness to confront the threat.
Stress causes several physiological changes, including increased alertness, accelerated breathing and heart rate, high blood pressure, and increased muscle tension.
Dr. Koch explains that when stress activates the “fight-or-flight response” in the central nervous system, this may be reflected in the digestive system through:
- Causing esophageal spasms.
- Increased secretion of stomach acids, leading to indigestion.
- Feeling nauseous.
- Diarrhea or constipation.
Also, stress may lead to an imbalance between gut bacteria, which may cause the immune system to become overactive and trigger inflammatory responses that may contribute to mental health problems. Among them are depression and anxiety.
Stress may also exacerbate a number of digestive disorders; Most notable:
- Irritable bowel syndrome (IBS).
- Inflammatory bowel disease (IBD).
- Peptic ulcer.
- Gastroesophageal reflux disease (GERD), also known as acid reflux.
Dr. Koch says: “Although stress may not be the direct cause of stomach ulcers or inflammatory bowel disease, it may exacerbate these two diseases, along with other diseases that affect the digestive system.”
Therefore, it is important to take the necessary measures to deal with stress better and reduce its effects on the body.
Intermittent fasting has gained increasing popularity over the past few years; Studies indicate that it may provide several health benefits, including preventing type 2 diabetes, weight loss, improving heart health, and possibly reducing the risk of Alzheimer's disease.
Jonathan R. said: Ruiz, Ph.D., a professor at the School of Sports Sciences at the University of Granada in Spain, told Medical News Today: “Intermittent fasting is a simple and practical nutritional strategy that is easy for participants to follow, and relatively easy for specialists to explain and describe.”
Ruiz is one of the lead authors of a study published in the journal Nature Medicine, the results of which indicate that following an “early” pattern of time-restricted intermittent fasting, which depends on eating during specific hours of the day and fasting the rest of the time, so that the fasting period extends from after five o’clock in the evening until about ten o’clock in the morning the next day, may be more beneficial in improving the regulation of blood sugar levels and reducing the amount of subcutaneous fat in the abdominal area.
Does the timing of fasting matter?
In this study, the researchers recruited about 200 participants, whose ages ranged between 30 and 60 years, and whose body mass index (BMI) was more than 32.
The participants were randomly distributed into four groups, which included the early fasting group, whose members ate during an average period that extended from 9:45 a.m. to 5:30 p.m., the late fasting group, whose eating period extended on average from 2:20 p.m. to 9:30 p.m., a group whose members chose the timing of fasting themselves, and a group that received usual care.
Study participants also received nutritional guidance on the “Mediterranean diet” and healthy lifestyles.
“Research in animal models has indicated that aligning mealtimes with circadian rhythms may enhance metabolic efficiency and improve health outcomes,” Ruiz explained.
He added: “We wanted to know whether these results also apply to humans, and how the timing of the eating period, whether early, late, or according to the participant’s own choice, affects weight loss, fat distribution, and cardiometabolic health in men and women who are overweight or obese.”
Early fasting reduces the amount of belly fat
After analyzing the results, Ruiz and his team found that all groups that followed the time-restricted fasting regimen, regardless of the timing of eating, achieved greater weight loss, ranging on average between 3 and 4 kilograms, compared to the group that received usual care.
Ruiz said: “This result confirms the effectiveness of eating within a specific time frame, as a simple, non-restrictive dietary approach to weight control. “The results show that this pattern may be a successful strategy for reducing body weight, regardless of the timing of the eating period, giving individuals the flexibility to choose an approach that suits their lifestyle.”
The researchers also discovered that participants who followed the early fasting system recorded a greater reduction in the amount of subcutaneous fat in the abdominal area, in addition to a noticeable improvement in glucose levels during fasting and during the night hours.
Ruiz added: “Our next steps include studying the long-term effects of eating within a specific time frame on bone density and other key health indicators. “We also want to explore whether combining time-bound eating and exercise has greater benefits than either alone in terms of managing body weight and improving body composition, reducing the accumulation of abnormal fat (fat outside adipose tissue), and improving cardio-metabolic health.”
A study conducted by researchers from the Danish University of Copenhagen revealed that regular consumption of coffee may affect not only the composition of bacteria in the intestines, but also the functions of the digestive system and the way it works, in results that may pave the way for a better understanding of bowel movement disorders, and perhaps the development of new methods for dealing with constipation.
It showed that people who drink coffee regularly have a greater diversity of microorganisms in the intestines compared to those who drink it less frequently, as well as differences in the physiology of the digestive system, that is, the processes and functions that occur within it. The results were published on Tuesday in the journal Gut Microbiology.
To reach these results, the research team asked a group of Danish participants to swallow a small electronic capsule, which was designed to measure a set of indicators as it travels through the digestive system, including the time it takes food to pass through the digestive tract, temperature, acidity levels, and intestinal contractions.
The researchers classified the participants into two groups: The first included people who drank coffee regularly, at a rate ranging between one and 5 cups per day on more than 3 days out of the 8 days included in the study, while the second included those who drank it less frequently.
The results showed that regular coffee consumption was associated with an increase in the diversity of microorganisms in the intestine, consistent with the results of previous studies, but researchers also observed differences in digestive system functions in regular coffee consumers.
The study's lead researcher, Francesca Bucci, from the University of Copenhagen, said that regular coffee consumption appears to affect the physiology of the intestine itself, and not just the composition of the bacteria present in it.
She added on the university's website that people who drink coffee regularly have significantly lower acidity levels in the small intestine compared to those who drink it less frequently, and high coffee consumption has also been linked to increased colon contractions.
Intestinal contractions play an important role in the digestion process, as they help move the contents of the digestive system, and may contribute to preventing constipation and maintaining the efficiency of the intestinal muscles. Bucci explained that these contractions support healthy digestion and help regular bowel movements.
However, researchers were unable to determine whether low acidity in the small intestine is beneficial or harmful to health, as pH plays an important role in the activity of digestive enzymes and breaking down food.
The researchers stressed that the results of the study do not prove that coffee is the direct cause of these differences, although there are indications that support its possible effect on the functions of the digestive system.
The team believes that “the next step is to conduct an interventional study in which researchers control the amounts of coffee consumed by participants, to compare changes in bowel function during periods of consumption and periods of abstinence.”
The researchers hope that “these results will contribute to understanding the mechanisms of coffee’s effect on digestion and bowel movement, which may help in the future to develop natural means to stimulate digestive system movement and deal with constipation, which a large number of people suffer from.”
