This randomized, double-blind, placebo-controlled clinical trial aims to evaluate the effects of agave inulin supplementation on metabolic profile and intestinal abundance of Bifidobacterium and Lactobacillaceae in adults with type 2 diabetes mellitus. Participants will receive either 10 g/day of agave inulin or a placebo for eight weeks. Clinical, anthropometric, biochemical, and gut microbiota assessments will be performed at baseline and at the end of the intervention. The study seeks to determine whether agave inulin supplementation improves metabolic outcomes and modulates beneficial intestinal microorganisms associated with metabolic health in adults with type 2 diabetes mellitus.

This randomized, double-blind, placebo-controlled, parallel-group clinical trial will evaluate the effects of agave inulin supplementation on metabolic profile and intestinal abundance of Bifidobacterium and Lactobacillaceae in adults with type 2 diabetes mellitus (T2DM).

Participants will be randomly assigned to receive either agave inulin (10 g/day) or placebo for eight weeks. The intervention will be administered as two daily doses of 5 g consumed before breakfast and before dinner.

Metabolic assessments will be performed at baseline and week 8 and will include fasting glucose, fasting insulin, glycated hemoglobin (HbA1c), insulin resistance (HOMA-IR), total cholesterol, LDL-cholesterol, HDL-cholesterol, and triglycerides. Anthropometric and body composition measurements, including body weight, body mass index (BMI), waist circumference, body fat percentage, and muscle mass percentage, will also be evaluated.

Fecal samples will be collected at baseline and week 8, preserved in DNA/RNA Shield solution, and stored at -80°C until analysis. Microbial DNA will be extracted using the ZymoBIOMICS™ DNA Miniprep Kit. Gut microbiota characterization will be performed through 16S rRNA gene sequencing of the V4 hypervariable region using primers 515F and 806R on the Illumina MiSeq platform. Bioinformatic analyses will be conducted using the QIIME pipeline to determine the abundance of Bifidobacterium and Lactobacillaceae. Statistical analyses will be performed according to the intention-to-treat principle.

Inclusion Criteria:

• Confirmed diagnosis of type 2 diabetes mellitus.
• Age between 20 and 75 years.
• Residence in Querétaro, Mexico.
• Stable oral hypoglycemic treatment and/or basal insulin.
• Ability to provide informed consent.

Exclusion Criteria:

• HbA1c > 9.5%.
• Current use of probiotics, prebiotics, synbiotics, or fiber supplements within the previous 3 months.
• Use of alpha-glucosidase inhibitors.
• Severe cardiovascular disease.
• Chronic kidney disease stage 3b or higher.
• Active gastrointestinal disease.
• Pregnancy or lactation.
• Known allergy to agave or fructans.

Individual participant data (IPD) will not be shared because participant consent for public data sharing was not obtained, and no formal data-sharing plan or repository was established at the time of study initiation. Data will be used solely for the purposes described in the approved research protocol and in accordance with institutional ethical guidelines.

Participants and investigators will remain blinded to treatment allocation throughout the study. Agave inulin and placebo will be provided in identical sachets with similar appearance, texture, and packaging. Treatment codes will remain concealed until completion of data collection.