{"id":7369,"date":"2026-01-21T17:33:12","date_gmt":"2026-01-21T16:33:12","guid":{"rendered":"https:\/\/bacteria.de\/?post_type=insight&#038;p=7369"},"modified":"2026-01-21T17:39:57","modified_gmt":"2026-01-21T16:39:57","slug":"alcohol-produced-in-the-gut","status":"publish","type":"insight","link":"https:\/\/bacteria.de\/en\/insight\/alcohol-produced-in-the-gut\/","title":{"rendered":"Drunk without alcohol"},"content":{"rendered":"\n<h1 class=\"wp-block-heading\">Auto-Brewery Syndrome (ABS): When the intestine produces alcohol<\/h1>\n\n<p><\/p>\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>If someone roams the streets slurring their words, it is immediately assumed that they have had too much to drink.<br\/>But what if the person has not had a glass of alcohol at all?<br\/>What if they are drunk through no fault of their own?<\/p>\n<\/blockquote>\n\n<p>In <strong>auto-brewery syndrome<\/strong>, those affected develop measurable blood alcohol levels even though they have not consumed alcohol. In the study discussed here, the focus is not on yeasts, but on a functionally altered intestinal microbiome that activates certain metabolic pathways and thus produces ethanol. <\/p>\n\n<p>It is not so much the specific composition of the <strong>intestinal microbiome<\/strong> that is decisive, but rather the unique <strong>biochemical interaction<\/strong> of the microorganisms. Under certain conditions, such as high carbohydrate availability, alcohol can be produced in the gut. The syndrome is rare and can be clearly distinguished from classic alcohol consumption. Nevertheless, those affected are often stigmatized.   <\/p>\n\n<p><\/p>\n\n<figure class=\"wp-block-image size-full is-resized\"><img decoding=\"async\" width=\"2912\" height=\"1632\" src=\"https:\/\/bacteria.de\/wp-content\/uploads\/2026\/01\/microorganisms.png\" alt=\"\" class=\"wp-image-7345\" style=\"aspect-ratio:1.7843182340767993;width:769px;height:auto\" srcset=\"https:\/\/bacteria.de\/wp-content\/uploads\/2026\/01\/microorganisms.png 2912w, https:\/\/bacteria.de\/wp-content\/uploads\/2026\/01\/microorganisms-1280x717.png 1280w, https:\/\/bacteria.de\/wp-content\/uploads\/2026\/01\/microorganisms-980x549.png 980w, https:\/\/bacteria.de\/wp-content\/uploads\/2026\/01\/microorganisms-480x269.png 480w\" sizes=\"(min-width: 0px) and (max-width: 480px) 480px, (min-width: 481px) and (max-width: 980px) 980px, (min-width: 981px) and (max-width: 1280px) 1280px, (min-width: 1281px) 2912px, 100vw\" \/><\/figure>\n\n<p><\/p>\n\n<h2 class=\"wp-block-heading\">What was done?<\/h2>\n\n<p>The study examined an observational study with<\/p>\n\n<ul class=\"wp-block-list\">\n<li>22 patients <strong>with<\/strong> auto-brewery syndrome<\/li>\n\n\n\n<li>21 <strong>unaffected<\/strong> household partners as a control group<\/li>\n<\/ul>\n\n<p>This is a classic <strong>multi-omics approach.<\/strong><\/p>\n\n<p><\/p>\n\n<h3 class=\"wp-block-heading\">These were carried out:<\/h3>\n\n<ol class=\"wp-block-list\">\n<li>Measurement of <strong>ethanol production<\/strong> from stool samples<\/li>\n\n\n\n<li>Analysis of <strong>microbial composition<\/strong> and functional genes with a focus on <strong>ethanol-relevant metabolic pathways<\/strong><\/li>\n\n\n\n<li>Measurement of central <strong>metabolites<\/strong>, including <strong>short-chain fatty acids<\/strong>, and correlation with blood alcohol levels<\/li>\n\n\n\n<li>Fecal <strong>microbiota transplantation<\/strong> in a patient with subsequent therapy observation<br\/><\/li>\n<\/ol>\n\n<div class=\"wp-block-divi-layout\">[et_pb_section fb_built=&#8221;1&#8243; _builder_version=&#8221;4.27.5&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;][et_pb_row _builder_version=&#8221;4.27.5&#8243; _module_preset=&#8221;default&#8221; custom_margin=&#8221;0px|||1px|false|false&#8221; global_colors_info=&#8221;{}&#8221;][et_pb_column type=&#8221;4_4&#8243; _builder_version=&#8221;4.27.5&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;][et_pb_toggle title=&#8221;Why is auto-brewery syndrome dangerous?&#8221; _builder_version=&#8221;4.27.5&#8243; _module_preset=&#8221;default&#8221; title_level=&#8221;h4&#8243; title_font_size=&#8221;19px&#8221; background_color=&#8221;rgba(45,172,220,0.13)&#8221; hover_enabled=&#8221;0&#8243; border_radii=&#8221;on|3px|3px|3px|3px&#8221; box_shadow_style=&#8221;preset1&#8243; global_colors_info=&#8221;{}&#8221; sticky_enabled=&#8221;0&#8243;]<p><strong>Auto-brewery syndrome (ABS)<\/strong> is dangerous because it leads to uncontrolled and often unnoticed production of ethanol in the gut, which poses medical as well as social and legal risks.<\/p>\n<p>&nbsp;<\/p>\n<h3><strong>A. Physical health and organ damage<\/strong><\/h3>\n<p>1. <strong>liver damage:<\/strong> constant exposure to endogenously produced alcohol leads to liver damage, which manifests itself in increased levels of alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (AP) and total bilirubin.<\/p>\n<p><strong>2. cirrhosis:<\/strong> In severe cases, chronic alcohol exposure through the microbiome can lead to liver cirrhosis.<\/p>\n<p><strong>3. metabolic diseases:<\/strong> Pathological ethanol production in the intestine is associated with the development of metabolic steatotic<br>liver disease (MASLD). Not yet confirmed. <\/p>\n<p><strong>4. neuro-psychiatric symptoms:<\/strong> patients suffer from extreme drowsiness and personality changes such as potentially increased aggression.<\/p>\n<p>&nbsp;<\/p>\n<h3><strong>B. Dangers in everyday life and legal risks<\/strong><\/h3>\n<p><strong>1. high blood alcohol concentration (BAC):<\/strong> During acute episodes (&#8220;flares&#8221;), average BAC values of 136 +\/- 82 mg\/dl were measured, which is well above the US limit for driving ability (80 mg\/dl).<\/p>\n<p><strong>2. legal problems:<\/strong> As with alcohol dependence, those affected often experience serious legal consequences, for example by drinking and driving without ever having drunk.<\/p>\n<p><strong>3. unpredictable intoxication:<\/strong> Since alcohol is produced spontaneously by the fermentation of carbohydrates in the intestine, intoxication often occurs completely unexpectedly.<\/p>\n<p>&nbsp;<\/p>\n<h3><strong>C. Social stigmatization and misdiagnosis<\/strong><\/h3>\n<p><strong>1. suspicion of secret drinking:<\/strong> Many patients are wrongly labeled as &#8220;secret drinkers&#8221; by doctors or their social environment and are not taken seriously.<\/p>\n<p><strong>2. diagnostic hurdles:<\/strong> Diagnosis is extremely resource-intensive and often not easily accessible or covered by insurance, leaving many sufferers without help for long periods of time.<\/p>\n<p><strong>3. burden on the environment:<\/strong> the disease leads to serious family and social problems that are comparable to the effects of alcohol addiction.<\/p>[\/et_pb_toggle][\/et_pb_column][\/et_pb_row][\/et_pb_section]<\/div>\n\n<p><\/p>\n\n<h2 class=\"wp-block-heading\">What does that mean?<\/h2>\n\n<p>The study provides strong evidence that <strong>auto-brewery syndrome <\/strong>in this cohort is primarily associated with <strong>bacterial metabolic pathways<\/strong>. Contrary to previous assumptions, yeasts did not play a dominant role here. <\/p>\n\n<p><\/p>\n\n<h3 class=\"wp-block-heading\"><strong>Key observations:<\/strong><\/h3>\n\n<ol class=\"wp-block-list\">\n<li>The production of ethanol was functionally <strong>measurable<\/strong><\/li>\n\n\n\n<li>The focus was on the <strong>pathway level<\/strong>, not on individual species<\/li>\n\n\n\n<li>Microbial metabolism correlated with <strong>blood alcohol levels<\/strong><\/li>\n\n\n\n<li>In addition to <em>Escherichia coli<\/em> and <em>Klebsiella pneumoniae<\/em>, other taxa, including <em>Ruminococcus gnavus<\/em>, were also enriched during acute episodes, although their direct role in ethanol production has not been conclusively clarified<br\/><\/li>\n<\/ol>\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>This clearly shows that pure sequence data does not tell a story. Only a look at the microbial reality, including the metabolism, reveals the truth. <\/p>\n\n\n\n<p><\/p>\n<\/blockquote>\n\n<p>Not every enrichment of proteobacteria led to ethanol production. Only the combination of substrate availability, enzyme equipment and microbial community dynamics produces the observed effect. <\/p>\n\n<p>In addition, it was found that acetate in the stool of auto-brewery syndrome patients was significantly increased and correlated strongly with the blood alcohol concentration. Acetate is a central metabolic product in ethanol metabolism. <\/p>\n\n<p><\/p>\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>The focus is therefore clearly on the microbial ecosystem.<\/p>\n<\/blockquote>\n\n<p><\/p>\n\n<figure class=\"wp-block-image size-full is-resized\"><img decoding=\"async\" width=\"2912\" height=\"1632\" src=\"https:\/\/bacteria.de\/wp-content\/uploads\/2026\/01\/sequenzdaten.png\" alt=\"\" class=\"wp-image-7349\" style=\"aspect-ratio:1.7843182340767993;width:720px;height:auto\" srcset=\"https:\/\/bacteria.de\/wp-content\/uploads\/2026\/01\/sequenzdaten.png 2912w, https:\/\/bacteria.de\/wp-content\/uploads\/2026\/01\/sequenzdaten-1280x717.png 1280w, https:\/\/bacteria.de\/wp-content\/uploads\/2026\/01\/sequenzdaten-980x549.png 980w, https:\/\/bacteria.de\/wp-content\/uploads\/2026\/01\/sequenzdaten-480x269.png 480w\" sizes=\"(min-width: 0px) and (max-width: 480px) 480px, (min-width: 481px) and (max-width: 980px) 980px, (min-width: 981px) and (max-width: 1280px) 1280px, (min-width: 1281px) 2912px, 100vw\" \/><\/figure>\n\n<p><\/p>\n\n<h2 class=\"wp-block-heading\">What impact will this have one day?<\/h2>\n\n<p>Since bacterial metabolic pathways played a <strong>central role <\/strong>in this study, this opens up the possibility of more targeted therapeutic approaches in the future.<\/p>\n\n<p>In the study, one patient underwent <strong>FMT<\/strong> (fecal microbiota transplantation) treatment, with a clear subsequent clinical improvement. <\/p>\n\n<p>In the long term, the treatment of auto-brewery syndrome could move away from blanket interventions such as non-specific antibiotics towards targeted modulation of microbial metabolic pathways and interactions.<\/p>\n\n<p><\/p>\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>The decisive factor here is the combination of ecological classification and functional analysis. This provides insights that pure sequence data cannot deliver. <\/p>\n<\/blockquote>\n\n<p><\/p>\n\n<p>In the future, analyses of the microbiome will increasingly focus on <strong>holistic approaches<\/strong>. Understanding the <a href=\"https:\/\/bacteria.de\/en\/body\/microbiome-diversity-health\/\">entire system<\/a> is becoming increasingly necessary. <\/p>\n\n<p><\/p>\n\n<h2 class=\"wp-block-heading\">Source:<\/h2>\n\n<p>Hsu, C. L. et al. Gut microbial ethanol metabolism contributes to auto-brewery syndrome in an observational cohort. Nature Microbiology, 2026.    <a href=\"https:\/\/www.nature.com\/articles\/s41564-025-02225-y\" target=\"_blank\" rel=\"noreferrer noopener\">DOI: 10.1038\/s41564-025-02225-y<\/a><\/p>\n\n<p><\/p>\n\n<div class=\"wp-block-divi-layout\">[et_pb_section fb_built=&#8221;1&#8243; _builder_version=&#8221;4.27.4&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;][et_pb_row _builder_version=&#8221;4.27.4&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;][et_pb_column type=&#8221;4_4&#8243; _builder_version=&#8221;4.27.4&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221;][dsm_text_divider header=&#8221;The most important facts at a glance&#8221; _builder_version=&#8221;4.27.5&#8243; _module_preset=&#8221;default&#8221; header_level=&#8221;h2&#8243; header_font=&#8221;||||||||&#8221; header_text_color=&#8221;#2DACDC&#8221; max_width=&#8221;100%&#8221; custom_margin=&#8221;||24px|||&#8221; custom_padding=&#8221;||14px||false|false&#8221; global_colors_info=&#8221;{}&#8221;][\/dsm_text_divider][et_pb_text module_class=&#8221;insight-box&#8221; _builder_version=&#8221;4.27.5&#8243; _module_preset=&#8221;default&#8221; background_color=&#8221;rgba(45,172,220,0.15)&#8221; custom_padding=&#8221;20px|70px|20px|70px|false|false&#8221; hover_enabled=&#8221;0&#8243; custom_css_free_form=&#8221;||.insight-box {||  max-width: 720px;       \/* Breite begrenzen *\/||  margin-left: auto;      \/* zentriert *\/||  margin-right: auto;||  background: linear-gradient(180deg, rgba(45,172,220,0.08) 0%, rgba(45,172,220,0.14) 100%);||  border-radius: 18px;||  box-shadow: 0 8px 22px rgba(0,0,0,0.05);||  padding: 30px 38px;||}||||\/* Magazin-Stil f\u00fcr Insights \/ Flash *\/||.insight-box {||  background: linear-gradient(180deg, rgba(45,172,220,0.08) 0%, rgba(45,172,220,0.14) 100%);||  border-radius: 18px;||  box-shadow: 0 8px 22px rgba(0,0,0,0.05);||  padding: 30px 38px;||  position: relative;||}||.insight-box::before {||  content: %22%22;||  position: absolute;||  top: 0; left: 0; bottom: 0;||  width: 4px;||  border-radius: 18px 0 0 18px;||  background: linear-gradient(180deg, rgba(45,172,220,0.5) 0%, rgba(45,172,220,0.25) 100%);||}||.insight-box ol li,||.insight-box ul li { margin-bottom: 30px; }||.insight-box ol li:last-child,||.insight-box ul li:last-child { margin-bottom: 0; }||||||||&#8221; border_radii=&#8221;on|5px|5px|5px|5px&#8221; box_shadow_style=&#8221;preset1&#8243; box_shadow_horizontal=&#8221;1px&#8221; box_shadow_color=&#8221;rgba(10,6,6,0.2)&#8221; global_colors_info=&#8221;{}&#8221; sticky_enabled=&#8221;0&#8243;]<ol>\n<li>The auto-brewery syndrome can probably also be caused by proteobacteria and not only by yeasts. In this study, a functional enrichment of proteobacterial metabolic pathways was indeed associated with the phenotype. <\/li>\n<li>Understanding microbial ecology is necessary to explain complex phenotypes such as ABS.<\/li>\n<li>In future, ABS patients could be treated in a more targeted and functionally oriented way.<\/li>\n<\/ol>[\/et_pb_text][\/et_pb_column][\/et_pb_row][\/et_pb_section]<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Ethanol from the gut instead of the glass: How an altered microbiome in auto-brewery syndrome produces measurable blood alcohol levels.<\/p>\n","protected":false},"featured_media":7368,"template":"","meta":{"_et_pb_use_builder":"off","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"insight-topic":[281],"class_list":["post-7369","insight","type-insight","status-publish","has-post-thumbnail","hentry","insight-topic-medicine"],"_links":{"self":[{"href":"https:\/\/bacteria.de\/en\/wp-json\/wp\/v2\/insight\/7369","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/bacteria.de\/en\/wp-json\/wp\/v2\/insight"}],"about":[{"href":"https:\/\/bacteria.de\/en\/wp-json\/wp\/v2\/types\/insight"}],"version-history":[{"count":3,"href":"https:\/\/bacteria.de\/en\/wp-json\/wp\/v2\/insight\/7369\/revisions"}],"predecessor-version":[{"id":7372,"href":"https:\/\/bacteria.de\/en\/wp-json\/wp\/v2\/insight\/7369\/revisions\/7372"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/bacteria.de\/en\/wp-json\/wp\/v2\/media\/7368"}],"wp:attachment":[{"href":"https:\/\/bacteria.de\/en\/wp-json\/wp\/v2\/media?parent=7369"}],"wp:term":[{"taxonomy":"insight-topic","embeddable":true,"href":"https:\/\/bacteria.de\/en\/wp-json\/wp\/v2\/insight-topic?post=7369"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}