Research & Articles

Insights on oral-systemic health

Stay informed with the latest research on oral bacteria, fertility, pregnancy, and systemic health connections — written by Dr. Neusha Najafi, DDS.

Content Clusters

Explore our organized content clusters — each designed to take you from understanding the science to taking action.

Testing

At-Home Salivary Testing

Everything you need to know about at-home saliva tests — choosing, comparing, and interpreting results.

• Best At-Home Saliva Tests Guide

• Collection Methods & Best Practices

• Blood Test vs Pathogen Panel

• Understanding Your Results

Testing

Oral Microbiome Guide

What your oral microbiome reveals about your whole-body health — from heart disease to fertility to cognitive health.

• Oral Microbiome Test Guide

• At-Home Tests Comparison

• Results Interpretation

Research

Gum Disease & Alzheimer's

The groundbreaking research connecting P. gingivalis to cognitive decline — and what you can do about it.

• Gum Disease & Alzheimer's

• P. Gingivalis Deep Dive

• F. Nucleatum Bridge Pathogen

Pregnancy

Preconception & Fertility

Why oral diagnostics belong on the preconception checklist — the oral-to-placental pathway and what to do before pregnancy.

• Saliva & Preconception Fertility

• Clinician Brief for OB-GYNs & REIs

• F. Nucleatum Placental Invasion

Prevention

Prevention & At-Home Tools

Affordable screening tools and evidence-based prevention — from pH strips to oral probiotics.

• Salivary pH Testing Guide

• Best Oral Probiotics 2026

• Collection Methods & Best Practices

Pregnancy

PMOS & the Oral Microbiome: A Preconception Clinician Brief

How oral bacterial burden and periodontal inflammation worsen the insulin resistance at the core of PMOS (formerly PCOS) — and what the preconception visit can do about it.

8 min read

Testing

Preconception Salivary Biomarkers: A Clinician's Guide to the Read

What salivary biomarkers actually measure in the preconception window — microbial load, inflammatory mediators, and the threshold logic behind the read.

9 min read

Pregnancy

Preterm Birth & Low Birth Weight: A Preconception Clinician Brief

How periodontal disease and oral pathogen burden raise preterm birth and low birth weight risk — and what the preconception visit can do about it.

8 min read

Pregnancy

Preeclampsia & Periodontal Disease: A Preconception Clinician Brief

The fifth spoke in the preconception clinician wedge: the periodontal disease → preeclampsia evidence base for OB-GYNs and REIs, including the shared two-hit inflammatory model, who to screen at the preconception visit, and the case for preconception intervention over gestational treatment.

9 min read

Prevention

Ozone Therapy: An Educational Guide for Patients and Clinicians

An evidence-based educational overview of ozone therapy in periodontics — how it works, what the evidence shows, which oral pathogens it targets, and where it fits in a comprehensive periodontal protocol.

7 min read

Prevention

Laser Therapy in Periodontics: An Educational Guide

An educational guide to laser therapy in periodontics — the three main laser types (Nd:YAG, Er:YAG, diode), how they work, what the evidence shows for LANAP and adjunctive use, and which periodontal pathogens they target.

8 min read

Prevention

Guided Biofilm Therapy (GBT): An Educational Guide

An educational guide to Guided Biofilm Therapy (GBT) — the AIRFLOW, PERIOFLOW, and PIEZON protocol guided by biofilm disclosure, how it differs from traditional prophylaxis, what the evidence shows, and where it fits in periodontal maintenance.

7 min read

Pregnancy

Preconception Saliva Testing: The Clinician Ordering Pathway

The clinician capstone: a single ordering pathway that converts the four preconception evidence spokes (biomarkers, pathogens, male-partner, maternal periodontitis) into one actionable workflow for OB-GYNs and REIs — who to screen, what to order, how to interpret, when to treat, when to refer, and how to re-test.

10 min read

Research

Porphyromonas gingivalis: The Keystone Pathogen in Oral-Systemic Disease

The most-studied periodontal pathogen — found in arterial plaque, Alzheimer's brain tissue, and placental specimens. How P. gingivalis drives systemic inflammation through gingipains, where the evidence is strongest, and what you can do about it.

11 min read

Pregnancy

Male-Partner Salivary Testing: The Clinician Brief for the Fertility Workup

Periodontal pathogens transmit between intimate partners. A patient who reduces her oral pathogen load preconceptionally can be re-exposed by an untreated partner. Why couples' salivary screening belongs on the fertility workup.

8 min read

Pregnancy

Maternal Periodontitis & Adverse Pregnancy Outcomes: The Preconception Clinician Brief

Periodontal disease during pregnancy raises preterm birth risk by up to 7×. The preconception window is the last clinical moment to treat it before gestational physiology locks the inflammatory baseline. A citation-ready brief for OB-GYNs, MFM specialists, and periodontists.

9 min read

Pregnancy

Saliva & Preconception Fertility: Why Oral Diagnostics Belong on the Preconception Checklist

The preconception window is the last routine clinical moment where oral pathogen load can be measured and treated before pregnancy hormones lock the inflammatory baseline in place. Here's why salivary diagnostics deserve a place on your preconception checklist.

10 min read

Prevention

Best Oral Probiotics 2026: A Dentist's Guide to Oral Microbiome Health

Swallowing a gut probiotic won't fix your breath or your gums. The oral microbiome is a different ecosystem entirely — here's which strains actually work, why formulation matters more than CFU count, and the top products ranked by clinical evidence.

10 min read

Pregnancy

Oral Pathogens & Preconception Fertility: The Clinician Brief for OB-GYNs & REIs

A citation-ready clinician brief on the oral-to-placental pathway — FadA-mediated translocation, the P. gingivalis/red-complex preconception link, and which oral findings should trigger a referral.

9 min read

Testing

Salivary pH Testing at Home: A Beginner's Guide to Oral Health Screening

A $6 roll of pH strips can tell you more about your oral microbiome than most dental check-ups. Here's what salivary pH means, how to test it correctly, and when a low reading signals something worth investigating.

9 min read

Research

Fusobacterium Nucleatum: The Bridge Pathogen Linked to Cancer & Pregnancy Complications

Fusobacterium nucleatum is one of the most consequential oral bacteria — found in colorectal tumors, placental tissue, and linked to pregnancy loss. Here's what the research shows.

8 min read

Testing

At-Home Saliva Collection: Methods & Best Practices

Getting accurate saliva test results starts with proper collection. Here's exactly how to collect your sample — timing, prep, common mistakes, and what invalidates results.

6 min read

Testing

Your Oral Microbiome Is a Window Into Your Systemic Health

The mouth is not just the start of digestion — it's a frontline diagnostic surface. Here's what an oral microbiome test actually measures, the three test types available, and the five systemic conditions most closely tracked to your oral bacteria.

14 min read

Research

The Gum Disease and Alzheimer's Connection: What the Research Actually Shows

Periodontal disease raises Alzheimer's risk by 1.5–3× — but the research is more nuanced than the headlines suggest. A detailed review of the oral-systemic connection, key studies, and what you can actually do about it.

12 min read

Testing

Understanding Your Salivary Test Results: A Complete Guide

Got your saliva test results back? Here's how to read them, what the bacterial levels mean, and what actions to take next.

7 min read

Testing

Saliva Blood Test vs Oral Pathogen Panel: Which Should You Choose?

Not all saliva tests are the same. Here's how to decide between a salivary biomarker test and an oral pathogen panel based on your health goals.

6 min read

Research

P. Gingivalis: The Oral Bacteria Linked to Gum Disease & Systemic Health

Porphyromonas gingivalis is one of the most studied oral pathogens — linked to gum disease, heart disease, Alzheimer's, and pregnancy complications.

7 min read

Testing

Best At-Home Saliva Tests for Oral Microbiome Testing (2026 Guide)

A complete guide to at-home saliva testing — what these tests measure, how to choose the right one, and what to do with your results.

8 min read

Testing

Diagnostic Dialogues with Dr. Neusha Najafi, DDS

How a personal pregnancy loss led Dr. Najafi to salivary diagnostics — and why she now tests every patient for oral-systemic risk.

5 min read

Pregnancy

Hormonal Contraceptives and the Oral Microbiome: The Missing First Signal in Salivary Diagnostics

We're debating hormones while ignoring the environment they enter. The oral microbiome is the first ecosystem hormonal contraceptives encounter — and we're not assessing it.

7 min read

Research

2025 Research Roundup: Oral Health Beyond the Mouth

A landmark year for oral-systemic research — from the first oral bacteria link to Parkinson's to flossing reducing stroke risk by 22%.

8 min read

Pregnancy

Unexplained Infertility, Explained?

Up to 30% of infertility cases are labeled 'unexplained'—but could oral bacteria, inflammation, and partner microbiome sharing be part of the answer?

4 min read

Testing

Diagnostic Dialogues: My Journey with Salivary Testing

A personal conversation about discovering salivary diagnostics after pregnancy loss and how testing transformed my approach to patient care.

4 min read

Oral-Systemic

The Oral-Fertility Connection: What Your Dentist Isn't Telling You

30% of infertility cases are classified 'unexplained.' New research points to something your OB-GYN and dentist have never discussed with you — and your saliva may hold the missing answers.

8 min read

Oral-Systemic

Hormones, Menopause, and Your Gums

How hormonal shifts may influence gum sensitivity and inflammation.

3 min read

Oral-Systemic

Men's Health and the Oral Microbiome

How gum health may be linked to inflammation, circulation, and overall vitality.

3 min read

Oral-Systemic

How Kids Get Their First Oral Bacteria

Understanding how the family microbiome is shared.

3 min read

Testing

Why Saliva Testing Is Changing Preventive Health

How saliva may offer early insight into inflammatory and microbial patterns.

2 min read

Oral-Systemic

The Oral-Systemic Connection Explained Simply

How gum inflammation may be associated with whole-body health patterns.

3 min read

Pregnancy

Oral Health & Pregnancy: The Complete Clinical Guide

Pregnancy gingivitis, enamel erosion from morning sickness, and periodontal disease that raises preterm birth risk by up to 7×. A trimester-by-trimester guide to safe, evidence-based dental care during pregnancy.

10 min read