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. The immune system is typically categorized into the innate and adaptive immune response systems, both of which are essential components in the body’s defense against pathogens. Th17 cells also can be considered a type of helper T cells characterized by the production of interleukin 17.
Alcohol abuse suppresses multiple arms of the immune response, leading to an increased risk of infections. The course and resolution of both bacterial and viral infections is severely impaired in alcohol-abusing patients, resulting in greater patient morbidity and mortality. Multiple mechanisms have been identified underlying the immunosuppressive effects of alcohol. Analyses of alcohol’s diverse effects on various components of the immune system provide insight into the factors that lead to a greater risk of infection in the alcohol-abusing population. Some of these mechanisms are directly related to the pathology found in people with infections such as HIV/AIDS, tuberculosis, hepatitis, and pneumonia who continue to use and abuse alcohol.
Focus On: Alcohol and the Immune System
Cytokines are also proposed to cross the blood-brain barrier and produce sickness behavior (Watkins, Maier et al. 1995), which is comorbid with AUD (Dantzer, Bluthe et al. 1998). Ethanol administration (4g/kg) in male rats increased IL-6 but decreased TNF-α expression in PVN, an effect that was blunted or reversed after long-term ethanol self-administration (Doremus-Fitzwater, Buck et al. 2014). Cytokines can also modulate important behavioral functions including learning and memory (Hao, Jing et al. 2014) possibly due to their role in neuroplasticity (Sheridan, Wdowicz et al. 2014). Many gaps remain in our understanding of the stress response, its physiological basis in the HPA, axis and its role in modulating the effects of ethanol on host immunity. In summary, several in vitro and in vivo studies demonstrate that ethanol modulates the function of innate immune cells (monocytes and DCs) in a dose and time dependent manner (Figure 1).
Alcohol affects many organs, including the immune system, with even moderate amounts of alcohol influencing immune responses. Although alcohol can alter the actions of all cell populations involved in the innate and adaptive immune responses, the effect in many cases is a subclinical immunosuppression that becomes clinically relevant only after a secondary insult (e.g., bacterial or viral infection or other tissue damage). Alcohol’s specific effects on the innate immune system depend on the pattern of alcohol exposure, with acute alcohol inhibiting and chronic alcohol accelerating inflammatory responses. The proinflammatory effects of chronic alcohol play a major role in the pathogenesis of alcoholic liver disease and pancreatitis, but also affect numerous other organs and tissues. In addition to promoting proinflammatory immune responses, alcohol also impairs anti-inflammatory cytokines. Chronic alcohol exposure also interferes with the normal functioning of all aspects of the adaptive immune response, including both cell-mediated and humoral responses.
Gut Microbiota and Immune System
After drinking 10 to 12 units of alcohol, your co-ordination will be highly impaired, placing you at serious risk of having an accident. The high level of alcohol has a depressant effect on both your mind and body, which makes you drowsy. This information is based on the assumption that you have a normal tolerance to alcohol. But even if you’re not drinking enough to compromise your immune system, she said the research shows alcohol is a temporary solution, at best. Regular drinking can also affect overall mental health and well-being, in part because alcohol may worsen symptoms of certain mental health conditions, including anxiety, depression, and bipolar disorder.
In fact, in acute alcoholic hepatitis, the severity of clinical outcome and death correlates with serum levels of the proinflammatory cytokines, particularly TNFα (Frazier et al. 2011; McClain et al. 2004). The exact triggers for alcohol-induced inflammation in the different tissues are yet to be identified. Importantly, deficiency in TLR4, the major sensor of LPS, attenuates inflammation induced by chronic alcohol use in the liver, brain, and intestine (Hritz et al. 2008; Lippai et al. 2013a,b, does alcohol weaken your immune system 2014). However, LPS increase was not found in the brain, suggesting that other ligands and/or alcohol itself may activate TLR4 (Alfonso-Loeches et al. 2010; Lippai et al. 2013b). The human gut is the largest organ with immune function in our body, responsible for regulating the homeostasis of the intestinal barrier. A diverse, complex and dynamic population of microorganisms, called microbiota, which exert a significant impact on the host during homeostasis and disease, supports this role.
How does alcohol affect your immune system?
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 [77] and peptidoglycans [78]. However, studies showing the effect of alcohol on these microbiota derived metabolites are scarce. These observations could explain why animals drinking moderately generated a more robust response to MVA vaccination compared to controls and animals that drank to intoxication since these factors are critical for lymphocyte proliferation, T cell activation and effector function, and immune cell recruitment. In addition to laboratory studies confirming the impact of alcohol consumption on the innate immune system, several studies have looked at how heavy drinking can alter plasma cytokine levels. To this end, one study analyzed IL-10, IL-6, IL-18, and tumor necrosis factor α (TNF-α) levels in 25 non-treating seeking heavy drinkers after they had consumed an alcoholic drink.
For instance, increased morbidity and mortality, pulmonary virus titers, and decreased pulmonary influenza-specific CD8 T cell responses were reported in female mice infected with influenza that consumed 20% (w/v) ethanol in their drinking water for 4–8 weeks (Meyerholz, Edsen-Moore et al. 2008). Likewise, higher pathogen burden and decreased CD8 T cell immunity was observed in female mice administered ethanol at 15% (w/v) for 5 days and challenged with Listeria monocytogenes (Gurung, Young et al. 2009). Similar results have been seen in SIV infection of male nonhuman primates (Bagby, Stoltz et al. 2003, Molina, McNurlan et al. 2006, Poonia, Nelson et al. 2006, Marcondes, Watry et al. 2008). Alcohol modulates the function of nearly all components of the innate immune system, but the specific effects on inflammatory cell responses depend on the pattern of alcohol exposure (i.e., acute or chronic). In human monocytes or mouse macrophages, acute alcohol results in a decrease in TLR responses (i.e., TLR tolerance), which attenuates particularly production of the TNFα in response to a subsequent LPS stimulation (Bala et al. 2012; Mandrekar et al. 2009). Even a single episode of binge drinking can have measurable effects on the innate immune system, inducing a transient proinflammatory state within the first 20 minutes after alcohol ingestion, followed by an anti-inflammatory state 2 to 5 hours after alcohol ingestion (Afshar et al. 2015).
Alcohol’s Effects on Adaptive Immunity
After a child reaches the age of three, the bacterial composition of gut microbiota remains reasonably stable and is unique to everyone depending on different factors like genetics, diet, and different environmental factors. A healthy gut microbiota is characterized by its richness and diversity in its composition [4]. Nevertheless, studies have shown that the normal gut microbiota comprises mainly Bacteroidetes and Firmicutes as the dominant phyla, followed by Actinobacteria and Verrucomicrobia. These gut commensals play an important role in specific functions like nutrient and drug metabolism, protection against pathogens, maintenance of structural integrity of gut mucosal barrier, among others [5,6]. Alcohol also impacts the function of immune cells of the central nervous system (CNS), particularly astrocytes and microglia. Astrocytes are major glial cells that regulate neuronal function and CNS homeostasis.
- What’s more, a short period of binge drinking — let’s say a month — can cause a reduction in T cells.
- 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.
- This will leave you feeling badly dehydrated in the morning, which may cause a severe headache.
- Both innate and adaptive immunity rely on a multitude of different cells and molecules.