The goal of this clinical trial is to learn if a dietary supplement called ButyMixx can help people with ulcerative colitis in remission feel better and keep their intestines less inflamed.

ButyMixx contains:

• Sodium butyrate, a substance normally produced by our gut microbiota that helps protect the intestinal lining and reduce inflammation.
• A "beneficial" yeast (Kluyveromyces marxianus), similar to probiotics, which may support the balance of the intestinal microbiota.

It will also learn about the safety of dietary supplement. The main questions it aims to answer are:

• Does ButyMixx after 2 months of supplementation

  • Symptoms improve,
  • Quality of life improves,
  • Intestinal inflammation decreases ,
  • The gut microbiota becomes more "balanced"

• What medical problems do participants have when taking ButyMixx ?

Participants will:

• Take 2 sachets of ButyMixx per day for 8 weeks

• Before starting and at the end of the 8 weeks:

  • Provide a stool sample
  • Complete a quality-of-life questionnaire
  • Be assessed by a doctor using a symptom score

ButyMixx Study A novel natural supportive strategy for Ulcerative Colitis in remission What is ulcerative colitis? Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by recurrent inflammation of the colonic mucosa, leading to symptoms such as diarrhea, rectal bleeding, abdominal pain, and fatigue.

Even during clinical remission, when symptoms are minimal or absent, the intestinal mucosa often remains fragile and susceptible to new inflammatory flares.

For this reason, current research is increasingly focused not only on treating acute disease activity, but also on identifying strategies able to maintain mucosal health over time, improve quality of life, and reduce the risk of relapse.

The role of the gut microbiota

The human gut hosts a complex community of microorganisms, known as the gut microbiota, which plays a crucial role in:

• digestion and nutrient metabolism
• protection against pathogenic microorganisms
• regulation of immune responses
• maintenance of intestinal barrier integrity In patients with UC, this microbial ecosystem is frequently altered (a condition known as dysbiosis), even during remission. Restoring a balanced microbiota is therefore considered a key therapeutic target.

What is ButyMixx?

ButyMixx is a dietary supplement combining two natural components:

1. Sodium butyrate

   Butyrate is a short-chain fatty acid normally produced by bacterial fermentation of dietary fibers. It has several well-documented physiological functions:

   • it is the main energy source for colonocytes
   • supports epithelial repair and regeneration
   • exerts anti-inflammatory effects
   • contributes to the maintenance of intestinal barrier integrity In patients with UC, endogenous butyrate production is often reduced.

2. Kluyveromyces marxianus

This is a probiotic yeast, commonly found in kefir, whose probiotic potential has been investigated in preclinical models. Studies have shown that K. marxianus:

• survives gastrointestinal transit efficiently
• interacts with the host immune system
• reduces pro-inflammatory signaling
• supports a more balanced intestinal microbiota It is recognized as safe by both European and US regulatory authorities.

Rationale of the study

The study was designed to investigate whether the combination of butyrate and probiotic yeast may represent a natural adjunctive strategy to standard pharmacological therapy (e.g., mesalamine and/or biologics), with the aim of:

• maintaining lower levels of intestinal inflammation
• improving patients' quality of life
• supporting gut microbiota homeostasis
• potentially reducing the risk of disease relapse

Study population

A total of 40 patients will be enrolled, meeting the following criteria:

• age between 18 and 75 years
• diagnosis of ulcerative colitis in clinical remission
• stable background medical therapy Patients with active disease, other forms of colitis, ongoing intestinal infections, pregnancy, or recent use of antibiotics/probiotics will be excluded.

Study design and procedures Study duration

• 8 weeks Supplement administration
• Two sachets of ButyMixx daily, taken before meals Study visits

Two visits are scheduled:

Baseline visit (T0)

• Clinical symptom assessment

• Quality-of-life questionnaire administration

• Stool sample collection for:

  • fecal calprotectin (marker of intestinal inflammation)
  • gut microbiota analysis End-of-treatment visit (T1, after 8 weeks)

• Reassessment of symptoms and quality of life

• Repeat stool sample collection

• Recording of any adverse events

Study outcomes

The study aims to determine whether, after two months of supplementation:

• clinical symptoms improve
• quality of life increases
• intestinal inflammation decreases
• the gut microbiota shows a more balanced profile In parallel, the safety and tolerability of the supplement will be carefully evaluated.

Why is this study important?

If proven effective and safe, ButyMixx could become:

• a natural adjunct to pharmacological therapy
• a tool to support long-term intestinal health
• a strategy to reduce disease burden and improve daily well-being in patients with ulcerative colitis Contributing to a more comprehensive and preventive approach to disease management

Inclusion Criteria:

• Diagnosis of UC confirmed by clinical, endoscopic and histopathological evidence. Disease in remission phase confirmed by clinical, endoscopic and histopathological evidence.
• Age between 18 and 75 years old
• Ability of subject to participate fully in all aspects of this clinical trial.

Exclusion Criteria:

• Patients that have active UC, determined by clinical, endoscopic and histopathological evidence
• Known diagnosis of CD( Crohn disease), indeterminate colitis, ischemic colitis, radiation colitis, diverticular disease associated with colitis or microscopic colitis
• Positive stool culture for active C. difficile
• Pregnant women
• Patients under antibiotic and/or probiotic treatment within 10 days prior to Visit 1.

Individual participant data (IPD) will not be shared.