Gut Health and Probiotics: AI Visibility Market Discovery Index

Benchmark Summary

Questions This Section Answers

• Which brand led the gut health and probiotics benchmark in October 2026, and by how much?
• Which brands moved beyond normal variation across the baseline-to-current series?
• Was there any significant single-month decline during the October 2026 period?

Culturelle led the Gut Health and Probiotics benchmark in October 2026 with 81.7% valid recommendation coverage. The gap to the next brand was 30.0 points over Garden of Life. The month-over-month move from September 2026 to October 2026 stayed within normal variation for every brand, and no brand registered a significant single-month decline.

Looking at the full baseline-to-current series, the largest coverage increase was Pendulum, which rose from 5.2% valid recommendation coverage in July 2026 to 10.7% in October 2026, moving beyond normal variation. The largest coverage decline was Florastor, which fell from 44.4% valid recommendation coverage in July 2026 to 38.9% in October 2026, within normal variation. Pendulum has now risen in each of the three months since July 2026, and its presence rate moved up from 6.5% to 12.5% over the series. Renew Life also moved beyond normal variation, up 4.9 points from 14.8% to 19.7%. Seed Health rose from 42.5% to 46.8% over the series, though it slipped 1.6 points from its September 2026 peak. Culturelle has held the coverage lead in every month of the series.

The benchmark began with 800 prompt-surface observations in each month and produced 447 qualified observations in October 2026 after qualification.

Current Benchmark at a Glance

Qualified surface breadth counts the canonical AI/search surface families with at least one qualified observation: ChatGPT, Copilot, Gemini, Perplexity, AI Overviews, and AI Mode.

For the strategic interpretation of this benchmark, read CiteWorks Studio's analysis of How AI Search Is Recommending Gut Health and Probiotics

Research Scope and Qualification

Questions This Section Answers

• How did the 800 source prompt-surface observations narrow to 447 qualified benchmark observations?
• Which research stage explains the largest loss of observations?

The public benchmark is narrower than the raw collection universe by design. The table below shows how the October 2026 collection narrowed from 800 source prompt-surface observations to 447 qualified benchmark observations.

Brand-level percentages use the qualified observations as the public denominator, not the raw collection. For details, see AI Visibility Market Discovery Methodology.

Current Brand Standings

Questions This Section Answers

• Which probiotic brands rank at the top of the October 2026 standings, and where does each land by valid recommendation coverage?
• How do presence rate and valid recommendation coverage differ across the tracked brands?

All rates below use the 447 qualified benchmark observations in October 2026 as the public denominator, not the raw collection total.

How to Read the Standings

• Presence rate: Share of qualified observations where the brand is mentioned at all.
• Valid recommendation coverage: Share of qualified observations where the brand appears in a valid recommendation shortlist.
• Top-three rate: Share of qualified observations where the brand appears in the top three recommendations.
• Rank-one rate: Share of qualified observations where the brand is the first recommendation.
• Net sentiment: Positive mentions minus negative mentions divided by total mentions.

For formulas and denominator rules, see AI Visibility Market Discovery Metric Definitions.

Recommendation Coverage Movement

Questions This Section Answers

• Which brands posted the largest coverage increases and declines since the July 2026 baseline?
• Did any coverage movements exceed normal variation?

Largest Increase: Pendulum

Pendulum rose 5.5 points in valid recommendation coverage, from 5.2% in July 2026 to 10.7% in October 2026, moving beyond normal variation. Pendulum rose in each of the three months since July 2026, with the largest single-month move of 4.4 points landing between July and August 2026. Its presence rate moved up from 6.5% to 12.5%, while its rank-one rate sat at 0.4% in October 2026, down from 1.1% in July 2026. Pendulum's valid recommendation count reached 48 in October 2026, supporting a coverage rate of 10.7%.

Largest Decline: Florastor

Florastor declined 5.5 points in valid recommendation coverage, from 44.4% in July 2026 to 38.9% in October 2026, within normal variation. Florastor's largest single-month move of 4.8 points landed between July and August 2026, and its coverage has not recovered to its July level since. Its presence rate fell from 52.8% to 42.5%, while its top-three rate held near flat at 26.0% to 25.9%. Florastor's valid recommendation count was 174 in October 2026.

Category Leader: Culturelle

Culturelle remained the coverage leader at 81.7% valid recommendation coverage in October 2026, up from 79.1% in July 2026. Its rank-one rate rose from 26.7% to 32.4%, and its top-three rate climbed from 66.5% to 71.4%. Its presence rate moved down from 91.5% to 87.7%. Culturelle's valid recommendation count was 365 in October 2026.

Renew Life moved beyond normal variation, up 4.9 points from 14.8% to 19.7%, with its largest single-month move of 3.8 points landing between July and August 2026. Seed Health rose 4.3 points from 42.5% to 46.8% over the series, peaking at 48.4% in September 2026 before easing back in October 2026. Align Probiotics and Garden of Life both moved within normal variation across the series.

Recommendation Placement Snapshot

Questions This Section Answers

• Which brands show the strongest top-three and rank-one placement rates in October 2026?
• How can similar coverage levels still produce different first-position rates?

Coverage alone does not show how prominently a brand is recommended. Several brands show distinct patterns in how often they appear in the top three or as the first recommendation.

Similar coverage levels can still hide different first-position rates. Seed Health's 21.9% rank-one rate sits within 10.5 points of Culturelle's 32.4%, despite a 34.9-point coverage gap between the two brands.

Buyer-Intent Distribution

Questions This Section Answers

• Which buyer-intent classes were represented in the qualified observations for October 2026?
• Can price or head-to-head comparison questions be answered from this data?

All qualified observations in both months fell into the Brand Recommendation class of buyer intent.

The current public series measures Brand Recommendation discovery only and does not yet contain qualified observations in the Pricing & Value or Multi-Brand Comparison classes, so price and head-to-head comparison questions cannot be answered from this data.

Historical Measurement Record

Evidence and Source Layer

Questions This Section Answers

• What source-layer data does the benchmark retain for each observation?
• Does source presence prove that a citation caused a recommendation?

The benchmark is built from prompt-level observations that retain the query, AI/search surface, answer, brand outcome, recommendation placement, sentiment, and, where exposed, citations or attributable evidence sources. Source presence is evidence about the information environment. It is not automatically proof that the source caused the recommendation.

Scope Boundaries

• This benchmark does not measure market share.
• It does not measure attributable sales or revenue.
• It does not capture every possible AI response.
• It does not measure organic-search ranking.
• It does not measure social mention volume.
• It does not cover private or sponsored channels.
• It does not establish causality from a metric movement alone.

Top 10 Cited Domains

Questions This Section Answers

• Which domains were cited most often across AI platform responses in October 2026?
• How concentrated are citations among the top 10 domains versus the remaining unique domains?
• Which health and medical reference sources appear prominently, and which tracked brand domain appears in the top 10?

Across all AI platform responses in October 2026, the benchmark recorded 7,111 citations drawn from 1,631 unique domains.

Citations are broadly distributed: the top 10 domains account for a combined 27.5% of all citations across 1,631 unique domains, meaning the remaining 1,621 domains share the other 72.5%. One tracked brand's own domain appears in the top 10: culturelle.com ranks sixth with 177 citations (2.5%), cited across all six canonical AI/search surface families. Health and medical reference sources feature prominently, with healthline.com, pmc.ncbi.nlm.nih.gov, and webmd.com collectively accounting for 6.7% of citations, alongside general commerce and media platforms such as amazon.com, youtube.com, forbes.com, and fortune.com.

About This Benchmark

The LLM Authority Index AI Visibility Market Discovery Index tracks how often brands appear in AI-generated recommendations across six canonical AI/search surface families. It records presence, recommendation coverage, placement, and sentiment from qualified prompt observations.

• AI Visibility Market Discovery Methodology
• AI Visibility Market Discovery Metric Definitions
• AI Visibility Market Discovery Research Standards
• Modeled AI Visibility Authority Value

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