In particular, the levels of antibodies against liver-specific autoantigens are increased in patients with alcoholic liver disease and may promote alcohol-related liver damage. Finally, chronic alcohol exposure in utero interferes with normal T-cell and B-cell development, which may increase the risk of infections during both childhood and adulthood. Alcohol’s impact on T cells and B cells increases the risk of infections (e.g., pneumonia, HIV infection, hepatitis C virus infection, and tuberculosis), impairs responses to vaccinations against such infections, exacerbates cancer risk, and interferes does alcohol suppress immune system with delayed-type hypersensitivity. In contrast to these deleterious effects of heavy alcohol exposure, moderate alcohol consumption may have beneficial effects on the adaptive immune system, including improved responses to vaccination and infection. The molecular mechanisms underlying ethanol’s impact on the adaptive immune system remain poorly understood. Future studies should leverage the different models to uncover the molecular mechanisms underlying the dose-dependent impact of alcohol on immune function by investigating changes in gene expression patterns (Mayfield and Harris 2009).
However, in most cases, when referring to IMB, one usually refers to the populations of bacteria that have colonized our large intestine. 5IgA is an antibody that plays a critical role in immune responses in the mucous membranes. These membranes line the body cavities exposed to the external environment (e.g., the GI tract, respiratory tract, nostrils, mouth, or eyelids) and therefore are likely to come in contact with outside pathogens. Several studies have demonstrated the dose-dependent effect that alcohol has on preventing both monocytes and macrophages from binding to the bacterial cell wall component lipopolysaccharide (LPS).
Focus On: Alcohol and the Immune System
One of the most significant immediate effects of alcohol is that it affects the structure and integrity of the GI tract. For example, alcohol alters the numbers and relative abundances of microbes in the gut microbiome (see the article by Engen and colleagues), an extensive community of microorganisms in the intestine that aid in normal gut function. Alcohol disrupts communication between these organisms and the intestinal immune system.
If you use alcohol, try to keep it to one drink a day for women and two drinks for men. As described earlier for adult humans, alcohol can lead to increases in Ig levels during development, even if the numbers of mature B cells decrease. Thus, maternal alcohol consumption during pregnancy (12 mg/week for most of the pregnancy) increased IgE levels in the umbilical cord blood of the infants (Bjerke et al. 1994). Acetaldehyde is the toxic byproduct that contributes to tissue damage, alcohol dependence, and addiction (Zakhari 2006).
Alcohol and HIV Effects on the Immune System
Each T cell expresses a unique T-cell receptor (TCR) that confers specificity for one particular foreign molecule (i.e., antigen). Early studies already had indicated that chronic alcohol abuse (i.e., for 12 to 15 years) resulted in reduced numbers of peripheral T cells (Liu 1973; McFarland and Libre 1963). More recent studies confirmed this observation and showed that the lack of lymphocytes (i.e., lymphopenia) was as severe in people who engaged in a short period of binge drinking as it was in individuals who drank heavily for 6 months (Tonnesen et al. 1990). Interestingly, abstinence for 30 days was sufficient to restore lymphocyte numbers back to control levels (Tonnesen et al. 1990). Similar findings were obtained in animal models, where the number of T cells in the spleen decreased in mice fed a liquid diet (i.e., Lieber-DeCarli diet) containing 7 percent ethanol for as little as 7 days (Saad and Jerrells 1991) or 6 percent ethanol for 28 days (Percival and Sims 2000). Likewise, adult male Sprague-Dawley rats consuming liquid diets containing up to 12 g ethanol/kg/day for 35 days exhibited significantly reduced absolute numbers of T cells (Helm et al. 1996).
Alcohol exposure, and particularly chronic heavy drinking, affects all components of the adaptive immune system. Studies both in humans and in animal models determined that chronic alcohol abuse reduces the number of peripheral T cells, disrupts the balance between different T-cell types, influences T-cell activation, impairs T-cell functioning, and promotes T-cell apoptosis. Chronic alcohol exposure also seems to cause loss of peripheral B cells, while simultaneously inducing increased production of immunoglobulins.
Does Alcohol Weaken Your Immune System?
The change in emotions a person experiences between intoxicated and being sober can also motivate drinkers to drink more frequently, Koob explains. George Koob, a behavioral psychologist and the director of the National Institute on Alcohol Abuse and Alcoholism, agrees. «Even short-term alcohol misuse affects the immune system,» Koob tells Inverse. If you use it regularly, you may have the same breathing problems you can get from nicotine cigarettes.
Over time, drinking can also damage your frontal lobe, the part of the brain responsible for executive functions, like abstract reasoning, decision making, social behavior, and performance. Slurred speech, a key sign of intoxication, happens because alcohol reduces communication between your brain and body. This makes speech and coordination — think reaction time and balance — more difficult.
Effects on B-Cells
Interestingly, central neuroinflammation is maintained after cessation of alcohol consumption, compared to peripheral activation  and during periods of abstinence . Finally, in relation to the effect of alcohol on neuroinflammation, a study by Lowe et al. showed an attenuation of alcohol-induced neuroinflammation after reducing the gut bacterial load, as a result of antibiotic treatment . We could hypothesize that by reducing the gut bacterial load, lower amounts of bacterial components would reach the systemic circulation, leading to reduced activation of pro-inflammatory components. Alcohol-related alterations of immune surveillance also have been implicated in the development of cancer (Poschl and Seitz 2004). Reduced cell-mediated immunity was proposed as a potential explanation for the high incidence of head and neck cancer observed in alcoholic patients (Lundy et al. 1975). However, these studies are difficult to interpret, because several factors affect antitumor immunity in human alcoholics, including malnutrition, vitamin deficiencies, and liver cirrhosis.
The highest production of SCFAs occurs in the proximal colon, where they are quickly and efficiently absorbed, since only 10% of the acids are excreted with the feces . The rest of the SCFAs reach the circulatory system via the superior or inferior mesenteric vein, reaching the brain and crossing the blood–brain barrier thanks to monocarboxylate transporters thus being able to act as signaling molecules between the gut and the brain . Specifically, chronic alcohol consumption could reduce the SCFAs count through the reduction in some Firmicutes genera, such as Faecalibacterium and Ruminococcaceae, on which the production of SCFAs depends [75,76]. Furthermore, it has been described that alcohol consumption would also have effects on other microbiota derived metabolites, leading to increases in branched-chain amino acids  and peptidoglycans . However, studies showing the effect of alcohol on these microbiota derived metabolites are scarce. Much progress has been made in elucidating the relationship between alcohol consumption and immune function and how this interaction affects human health.
That dual action predisposes heavy drinkers both to increased infection and to chronic inflammation. These articles detail how alcohol affects the immune system and how researchers are harnessing this knowledge to help prevent and treat alcohol-related harm. “Alcohol has diverse adverse effects throughout the body, including on all cells of the immune system, that lead to increased risk of serious infections,” said Dr. E. Jennifer Edelman, a Yale Medicine addiction medicine specialist.
- The intestinal barrier is a semipermeable structure that allows the uptake of essential nutrients and immune sensing while being restrictive against pathogenic molecules and bacteria .
- But the investigators were surprised to find that the monkeys deemed as moderate drinkers demonstrated an enhanced vaccine response.
- These cells, known as T cells and B cells, originate in your bone marrow and are involved in the release of antibodies in your blood.
- These molecules help recruit and activate additional PMNs as well as macrophages to the site of an injury or infection.
- Although most research has focused on the effects of heavy alcohol consumption on the immune system, several studies have also confirmed that even moderate consumption can have significant effects on the immune system.