Odds Ratio Snapshot: Small intestinal bacterial overgrowth (SIBO)

This document presents the results of statistical analysis on symptoms from viable, self-annotated Biomesight microbiome samples. The methodology for data acquisition is outlined in New Standards for Microbiome Analysis?.

Tables have been refined to display only genus- and species-level taxa, the 20 most prominent entries per group, and associations achieving statistical significance (P < 0.01).

The following sections provide the processed data, accompanied by guidance on interpretation and application. Counts of significant bacterial taxa are included, reflecting the application of non-standard but rigorously validated statistical approaches to extensive sample and reference populations, where statistical power derives from dataset scale.

SignificanceGenus
p < 0.01182
p < 0.001164
p < 0.0001146
p < 0.00001130

Averages and Medians

I prefer medians over averages. Medians are the values where half of the people have less and half has more. If the data was a bell-curve, then the values will almost be the same… with bacteria that happens rarely. Look at the bacterua below, we see that for some the average is above and the median below. Should one increase or decrease this bacteria?

If symptom median is higher than reference median, it means there is more of this bacteria. If lower, then less. This ignores how often the bacteria is seen (we average only over reports). IMHO using average value instead of median will often result in a worse situation for the patient

tax_nameRankSymptom AvarageReference AverageSymptom MedianReference Median
Bacteroidesgenus31.10225.83424.21730.409
Faecalibacteriumgenus10.53112.87512.1559.178
Faecalibacterium prausnitziispecies10.19312.30111.478.958
Phocaeicola vulgatusspecies6.2835.7883.4274.247
Bacteroides uniformisspecies3.2292.711.5592.11
Ruminococcusgenus5.965.5864.3943.874
Coprococcusgenus1.3131.4360.7380.483
Clostridiumgenus2.0671.851.3591.612
Phocaeicola doreispecies3.7152.8730.4120.196
Bacteroides thetaiotaomicronspecies1.6121.0490.4630.593
Bacteroides cellulosilyticusspecies1.0920.8440.0750.179
Lachnospira pectinoschizaspecies0.5490.6680.3370.245
Ruminococcus bromiispecies0.7840.7910.1740.083
Bifidobacteriumgenus0.5740.950.1280.045
Bilophila wadsworthiaspecies0.3870.340.1990.273
Bilophilagenus0.3950.3480.2090.281
Lachnobacteriumgenus0.2220.3250.0760.028
Sutterella wadsworthensisspecies0.7110.6570.0590.011
Doreagenus0.4940.4820.2920.336
Hathewayagenus0.3810.2750.1550.198

Bacteria Incidence – How often is it reported

The common sense belief is that if a bacteria is reported more often, then the amount should be higher. This is often not true. The microbiome is a complex thing.

tax_nameRankIncidence Odds RatioChi2Symptoms %Reference %
Halanaerobiumgenus1.587.726.416.7

More or Less often based on Symptom Median All Incidence

This is a little more complex to understand. If we compute the mid point for people with the symptom, then if the bacteria was not involved then half of the reference should be above this value and half below this value. If not, it means that the symptom tends to over or under growth.

tax_nameRankSymptom MedianOdds RatioChi2BelowAbove
Isoalcanivoraxgenus0.0020.2653.937198
Isoalcanivorax indicusspecies0.0020.2653.937198
Alcanivoraxgenus0.0020.2753.8382102
Niabella aurantiacaspecies0.0020.3343.2545182
Pelagicoccus croceusspecies0.0020.3240.7378122
Psychrobacter glacialisspecies0.0020.3835.8660250
Niabellagenus0.0020.3835585221
Viridibacillus neideispecies0.0020.3832.9472179
Chromatiumgenus0.0020.3932.1515200
Chromatium weisseispecies0.0020.3932514200
Sporosarcina pasteuriispecies0.0020.428.6444179
Thiorhodococcusgenus0.0020.4227.4578245
Syntrophomonas sapovoransspecies0.0020.4227536227
Sporosarcinagenus0.0020.4226.9448186
Lysinibacillusgenus0.0020.4225.9401167
Thermodesulfovibrio thiophilusspecies0.0020.4523.5540243
Oenococcusgenus0.0020.4622.6601277
Thermodesulfovibriogenus0.0020.4722.1625292
Helicobacter suncusspecies0.0020.4821.7761363
Viridibacillusgenus0.0020.517.6486242

More or Less often based on Reference Median All Incidence

This is like the above, but with a different line in the sand. Instead of the median of those with the condition, we use the median of the reference set.

tax_nameRankReference MedianOdds RatioChi2BelowAbove
Lachnobacteriumgenus0.0282.0724311972474
Bifidobacterium longumspecies0.01352.14228.29001929
Paenibacillusgenus0.0030.38208.1999384
Erysipelothrixgenus0.0170.51205.722441135
Anaerobranca zavarziniispecies0.0051.98195.510462066
Anaerobrancagenus0.0051.98195.510462066
Erysipelothrix murisspecies0.0160.52191.421941135
Slackiagenus0.0091.9182.111612202
Legionella shakespeareispecies0.0030.37158.9659243
Bacteroidesgenus30.4090.57158.225111422
Faecalibacteriumgenus9.1781.76157.214232508
Niabella aurantiacaspecies0.0020.33155.3545182
Eubacterium callanderispecies0.0070.54155.218821016
Holdemaniagenus0.0270.56153.422221244
Psychrobacter glacialisspecies0.0020.38152.7660250
Bifidobacteriumgenus0.0451.73146.514132447
Methylonatrumgenus0.0040.54142.51617870
Methylonatrum kenyensespecies0.0040.54142.51617870
Amedibacillus dolichusspecies0.0220.54141.71678912
Amedibacillusgenus0.0220.54141.41677912

More or Less often based on Symptom Median High Incidence

Above we see that many of the top bacteria identified are sparse, that is not reported often. We then restrict them to those that occur above 50% or the time.

tax_nameRankSymptom Median FreqOdds RatioChi2BelowAbove
Clostridium taeniosporumspecies0.0030.6110.21349827
Dethiosulfovibriogenus0.0040.676.715051012

More or Less often based on Reference Median High Incidence

Above we see that many of the top bacteria identified are sparse, that is not reported often. We then restrict them to those that occur above 50% or the time.

tax_nameRankReference Median FreqOdds RatioChi2BelowAbove
Lachnobacteriumgenus0.0282.0724311972474
Bifidobacterium longumspecies0.01352.14228.29001929
Paenibacillusgenus0.0030.38208.1999384
Erysipelothrixgenus0.0170.51205.722441135
Anaerobranca zavarziniispecies0.0051.98195.510462066
Anaerobrancagenus0.0051.98195.510462066
Erysipelothrix murisspecies0.0160.52191.421941135
Slackiagenus0.0091.9182.111612202
Legionella shakespeareispecies0.0030.37158.9659243
Bacteroidesgenus30.4090.57158.225111422
Faecalibacteriumgenus9.1781.76157.214232508
Niabella aurantiacaspecies0.0020.33155.3545182
Eubacterium callanderispecies0.0070.54155.218821016
Holdemaniagenus0.0270.56153.422221244
Psychrobacter glacialisspecies0.0020.38152.7660250
Bifidobacteriumgenus0.0451.73146.514132447
Methylonatrumgenus0.0040.54142.51617870
Methylonatrum kenyensespecies0.0040.54142.51617870
Amedibacillus dolichusspecies0.0220.54141.71678912
Amedibacillusgenus0.0220.54141.41677912

Summary

A large number of bacterial taxa exhibit shifts with P < 0.01 in association with this condition. The subsequent challenge is determining how to modulate these taxa, since the volume of candidates exceeds what most individuals can practically consider. Moreover, for many of the taxa identified, there is no published evidence in the U.S. National Library of Medicine describing how to alter their abundance.

A deep optimization model, such as the one implemented on the Microbiome Taxa R2 site, can be used to inform probiotic selection. This model provides coverage for each identified taxon and infers which probiotics are most likely to shift their levels. Its output may then be integrated with more conventional recommendations derived from literature indexed in the U.S. National Library of Medicine where such evidence exists, with the two recommendation sets reconciled by giving priority to probiotic-based suggestions.

Development of a dedicated database based on Biomesight samples is in progress. The current model uses data contributed by PrecisionBiome, and datasets generated with differing laboratory processing pipelines cannot be safely combined, as discussed in The taxonomy nightmare before Christmas…. Once the Biomesight-specific database is complete, an option for generating (offline-only) personalized suggestions will be added to the Microbiome Prescription website.

Probiotics Suggestions

The following are based on a simplified algorithm using R2 data for Biomesight. These are tentative numbers subject to future refinements. Bacteria listed are only for probiotics detected with Biomesight tests. Probiotics include some that are available only in some countries and some that are pending approval for retail sale.

  • Good Count: Number of bacteria expected to shift in desired direction
  • Bad Count: Number of bacteria expected to shift in wrong direction
  • Impact: Estimator of impact based on Chi-2, Slope and R2 vectors
Probiotic SpeciesImpactGood CountBad Count
Faecalibacterium prausnitzii842.75130
Blautia hansenii196.62201
Blautia wexlerae129.1980
Segatella copri96.3580
Bifidobacterium breve64.71160
Bifidobacterium longum57.42170
Bifidobacterium adolescentis42.42160
Lactobacillus helveticus39.079834
Akkermansia muciniphila23.53244
Bifidobacterium bifidum13.29112
Bifidobacterium catenulatum11.2682
Escherichia coli8.6773
Bifidobacterium animalis6.0871
Bacillus subtilis1.264438
Clostridium butyricum0.961917
Veillonella atypica0.8366
Enterococcus faecium0.762214
Enterococcus durans0.662620
Limosilactobacillus fermentum0.51223
Streptococcus thermophilus0.3223
Bifidobacterium pseudocatenulatum0.222020
Limosilactobacillus vaginalis0.133738
Lactiplantibacillus pentosus0.1361
Ligilactobacillus salivarius0.0473
Lactiplantibacillus plantarum-0.0135
Lactococcus lactis-0.0345
Lactobacillus crispatus-0.0619
Lacticaseibacillus paracasei-0.1511
Lacticaseibacillus rhamnosus-0.1736
Lactobacillus acidophilus-0.181011
Leuconostoc mesenteroides-0.19711
Lacticaseibacillus casei-0.2208
Limosilactobacillus reuteri-0.351720
Lactobacillus jensenii-0.742624
Parabacteroides goldsteinii-6.8644
Pediococcus acidilactici-9.82148
Enterococcus faecalis-17.665951
Parabacteroides distasonis-22.6904
Lactobacillus johnsonii-58.414839
Bacteroides uniformis-547.16013
Bacteroides thetaiotaomicron-585.02011

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