Study of the Link Between MASH ( Metabolic Dysfunction-Associated Steatohepatitis) and MAMs (Mitochondria-Associated Membranes ) Alteration in Patients Undergoing Bariatric Surgery - MAMBA

* Inclusion Criteria \* : * Female or male adult patients * Patient who has benefited from a pluridisciplinary evaluation (medical, surgical, psychiatric), with a favorable opinion for a sleeve gastrectomy or a gastric bypass. * Patient with an indication Indication for intraoperative liver biopsy due to suspected MASH * Patient who agrees to be included in the study and who signs the informed consent form, * Patient affiliated to a healthcare insurance plan. * Exclusion Criteria \* : * Patient presenting Hepatitis B as defined as presence of hepatitis B surface antigen (HBsAg). * Patient presenting previous or current infection with Hepatitis C * Autoimmune hepatitis as defined by anti-nuclear antibody (ANA) of 1:160 or greater and liver histology consistent with autoimmune hepatitis or previous response to immunosuppressive therapy. * Patient presenting Autoimmune cholestatic liver disorders as defined by elevation of alkaline phosphatase and anti-mitochondrial antibody of greater than 1:80 or liver histology consistent with primary biliary cirrhosis or elevation of alkaline phosphatase and liver histology consistent with sclerosing cholangitis. * Patient presenting Wilson disease as defined by ceruloplasmin below the limits of normal and liver histology consistent with Wilson disease. * Patient presenting Alpha-1-antitrypsin deficiency as defined by alpha-1-antitrypsin level less than normal and liver histology consistent with alpha-1-antitrypsin deficiency. * Patient presenting Hemochromatosis as defined by presence of 3+ or 4+ stainable iron on liver biopsy and homozygosity for C282Y or compound heterozygosity for C282Y/H63D. * Patient presenting Drug-induced liver disease as defined on the basis of typical exposure and history. * Patient presenting Bile duct obstruction as shown by imaging studies. * History of ingestion of medications known to produce steatosis, such as corticosteroids, high-dose estrogen, tamoxifen, methotrexate, amiodarone or tetracycline in the previous 6 months. * Evidence of cirrhosis or previously known cirrhosis based on the results from previous liver biopsy or history of portal hypertension presented by ascites, hepatic encephalopathy or varices * Consommation régulière et/ou excessive d'alcool (plus de 30g/j pour les hommes et plus de 15 g/j pour les femmes) sur une période de plus de 2 ans au cours des 10 dernières années. * History of known HIV infection * History of type 1 diabetes * Pregnant women or breastfeeding mothers\*. * Minor patient * Patient deprived of liberty, * Patients under psychiatric care * Patients admitted to a health or social care establishment for purposes other than research * Mentally unbalanced patients, under supervision or guardianship, * Patients not affiliated to a social security scheme or benefiting from a similar scheme * Patient who does not understand French/ is unable to give consent, * Patient already included in a trial who may interfere with the study