Probiotics Use and Preventing Gastrointestinal Symptoms in People Living With Overweight and Obesity.

Inflammatory bowel disease (IBD) affects over 6.8 million people worldwide, with current treatments often causing side effects and poor patient compliance. Dysbiosis of gut microbiota is a key factor, and while probiotics are considered safe and beneficial, conventional strains fail to function effectively during active inflammation due to high iron levels in the gut. Streptococcus thermophilus (FX856), unlike traditional probiotics, can thrive in this iron-rich environment, promoting mucosal healing. A 2-way crossover intervention study will be conducted with FX856 supplementation in overweight and obese individuals who often exhibit mild gut inflammation by measuring faecal calprotectin and systemic inflammatory markers.

Study Overview

• Status: Enrolling by invitation
• Conditions: Gut Inflammation; Overweight and Obese Volunteers
• Intervention / Treatment: Dietary supplement: Probiotic Arm; Dietary supplement: Placebo Arm

Detailed Description

There is a lack of satisfactory treatments for inflammatory bowel disease (IBD), an excruciatingly debilitating condition which affects 1 in 123 people in the UK (>0.5million). Current treatments have significant negative side effects, affecting quality of life of patients and reducing compliance, leading to exacerbation of symptoms. Dysbiosis in the composition of gut microbiota is one of the leading causes of chronic inflammatory diseases such as inflammatory bowel disease (IBD). Supplementation with dietary components is a promising approach for the treatment of inflammatory bowel disease (IBD) and the use of probiotics for IBD treatment has shown promising effects on consumers' quality of life, they are popular due to their perception as safe, natural treatments but currently marketed products cannot function during active disease. Streptococcus thermophilus (FX856) is an OTC supplement already available in the UK that has a unique ability to survive and thrive during active inflammation, allowing it to promote mucosal healing in the inflamed gut, an area where conventional probiotics have failed. During active inflammation or stress, gut iron levels increase. This iron-rich environment compromises the suitability of conventional probiotic bacteria that have been, and are still, commonly trailed for the relief of symptoms in patients suffering from gut inflammation. Whilst most constituents of the gut microbiome are able to increase growth rate in response to iron, species traditionally employed as probiotics, such as lactobacilli and bifidobacteria, are unable to use iron as a growth factor; they are outcompeted under high iron conditions and cannot have a beneficial effect. Unlike most bacterial strains used as probiotics, FX856 can maintain growth within an iron-rich environment, as observed in the inflamed intestine. Faecal calprotectin is considered a suitable non-invasive surrogate marker of intestinal inflammation in inflammatory bowel disease and is reported to be increased in obese individuals. Consequently, this study will determine how the probiotic FX856 interacts with the gut and immune system to reduce inflammation. A 2-way crossover intervention study will be conducted with FX856 (4 weeks) in an overweight and obese population, as such individuals are likely to have chronic mild gut inflammation and examine markers of faecal calprotectin and circulating inflammatory markers.

• Study Type: Interventional
• Enrollment (Estimated): 100
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Coleraine, United Kingdom, BT52 1SA
    • Ulster University, Human Intervention Studies Unit

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Either a BMI 25+ kg/m2 and be aged 40+ years or have a BMI 30+ kg/m2 and aged 18+ years
• Males and females (not currently pregnant/lactating)
• Omnivorous diet (consuming plant & animal based foods)
• Not taking any medication affecting the gastro-intestinal tract
• No chronic gastro-intestinal illness
• Not using fibre supplements or any probiotic or prebiotic products, e.g., Fybogel, Actimel, kefir or kimchee for at least 6 weeks prior to study
• Not consuming 7+ units of alcohol per day (e.g. 3 medium glasses of wine ~12%)

Exclusion Criteria:

• Not aged 40+ years (if have a BMI 25-29.9 kg/m2)
• BMI<30 kg/m2 (if aged 18-39 years)
• Pregnant/lactating female
• Vegan/vegetarian/high protein diet
• Chronic gastro-intestinal illness
• Taking medication affecting the gastro-intestinal tract
• Taking fibre supplements or any probiotic or prebiotic products
• Consuming 7+ units of alcohol per day (e.g. 3 medium glasses of wine ~12%)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Probiotic Arm; Probiotic supplement arm, 2 capsules consumed/day for a period of 28 days.	Dietary supplement: Probiotic Arm; 1 x10^9 cfu Streptococcus thermophilus (FX856), corn starch, anti-caking agent in a hydroxypropylmethycellulose & pectin capsule.
Placebo Comparator: Placebo Arm; Placebo supplement arm, 2 capsules consumed/day for a period of 28 days.	Dietary supplement: Placebo Arm; corn starch, anti-caking agent in a hydroxypropylmethycellulose & pectin capsule.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Assess effects of FX856 on faecal calprotectin	The level of calprotectin in faecal samples will be measured by immunoassay in all participants to determine if FX856 consumption can decrease it.	Change over 28 days comparison between treatments

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Assess effect of FX856 treatment on gastrointestinal symptoms	Measured by questionnaire rated on scale from 0 (Dose not bother me at all) to 10 (Is as bad as I can imagine)	Change over 28 days comparison between treatments
Assess effect of FX856 on circulating inflammatory cytokines IFN-γ	Measured by ELISA	Change over 28 days comparison between treatments
Assess effect of FX856 on circulating inflammatory cytokines IL-1β	Measured by ELISA	Change over 28 days comparison between treatments
Assess effect of FX856 on circulating inflammatory cytokines IL-6	Measured by ELISA	Change over 28 days comparison between treatments
Assess effect of FX856 on circulating inflammatory cytokines TNF-α	Measured by ELISA	Change over 28 days comparison between treatments
Assess effect of FX856 on Cholesterol	Measured by ILab 650 chemistry analyser using CHOD-PAP/GPO-PAP colorimetric end-point assays.	Change over 28 days comparison between treatments
Assess effect of FX856 on LDL cholesterol	Measured by ILab 650 chemistry analyser using CHOD-PAP/GPO-PAP colorimetric end-point assays. LDL concentrations calculated using the Friedewald formula.	Change over 28 days comparison between treatments
Assess effect of FX856 on HDL cholesterol	Measured via ILab 650 chemistry analyser using CHOD-PAP/GPO-PAP colorimetric end-point assays.	Change over 28 days comparison between treatments
Assess effects of FX856 on microbiota	The composition of gut microbiota from faecal samples will be measured by NGS pre and post consumption in all participants to determine if FX856 consumption alters the gut microbiota.	Change over 28 days comparison between treatments
Assess effects of FX856 on faecal metabolome	The faecal metabolome from faecal samples will be measured by untargeted mass spec pre and post consumption in all participants to determine if FX856 consumption alters the faecal metabolome.	Change over 28 days comparison between treatments
Assess effects of FX856 on blood metabolome	The blood metabolome will be measured by untargeted mass spec pre and post consumption in all participants to determine if FX856 consumption alters the blood metabolome.	Change over 28 days comparison between treatments

Collaborators and Investigators

• Sponsor: University of Ulster
• Collaborators: Ferryx Limited
• Investigators: Principal Investigator: Chris Gill, PhD, Ulster University, Human Intervention Studies Unit, Coleraine, Co. Londonderry, BT52 1SA, United Kingdom.

Study record dates

Study Major Dates

• Study Start (Actual): October 14, 2025
• Primary Completion (Estimated): September 1, 2028
• Study Completion (Estimated): September 1, 2028

Study Registration Dates

• First Submitted: September 23, 2025
• First Submitted That Met QC Criteria: November 26, 2025
• First Posted (Actual): November 28, 2025

Study Record Updates

• Last Update Posted (Actual): November 28, 2025
• Last Update Submitted That Met QC Criteria: November 26, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Keywords: Obesity; overweight; metabolome; microbiota; gastrointestinal symptoms; gut inflammation
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Overweight; Obesity
• Other Study ID Numbers: REC/25/0042

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No