heavy metal detox

Heavy Metals and Candida

This is a summary of the notes on yeasts as part of our microbiome and the trouble they can cause when they interact with heavy metals Cd, Hg, and Pb. Sulfur seems to be a part of the trouble as these elements can sometimes form blood brain barrier. penetrating crystals. The featured images were obtained from an Internet search as indicated. These images serve as a reminder that the fungus among us have their ways of putting heavy metals in places that are less harmful to them. Are they less harmful to us too?,

Dr Raws and Yeast Advisor

What can we do to treat oral fungal growth? Are yeasts and mold doing bad things?

Yeast Infection Advisory seems like a really good site. The page on mercury seems to be a bit under scrutinized. Here is one of their references

Muzurovic S, Babajic E, Masic T, Smajic R, Selmanagic A. The relationship between oral hygiene and oral colonisation with Candida species. Med Arch. 2012;66(6):415-7. PubMed

A correlation between Candida, Hg fillings, and poor oral hygiene?

These authors came from Public Institution Medical Centre of the Sarajevo Canton, Sarajevo, Bosnia and Herzegovina.. Are the more expensive composite fillings even available in Bosnia? Are people with poor oral hygiene more likely to have both Candida infections and the need to have fillings in the first place? Perhaps the Bosnians were not trying to claim a causal relationship between amalgum fillings and Candida infections.

Abstract, response to yeast advisor

The aim of this study is to determine relationship between oral hygiene and colonization of Candida species in oral cavity.

Introduction: Maintenance oral hygiene is reducing pathological agents in the mouth and preventing violation of oral health.

Material and methods: Study included 140 patients. For oral hygiene assessment were used the dental plaque index, oral hygiene index and dental calculus index. pH test strips were used to determine pH of saliva. For isolation of Candida species oral swabs were taken to all patients.

Results: It was found out that pH of oral cavity does not varies notably, no matter of oral hygiene level. Candida species were identified in 28.6% respondents. The most present were Candida albicans, in 85% cases. The presence of plaque, tartar and high index oral hygiene (IOH) in patients with Candida is statistically significant. It was found that 83.4% of patients with Candida poorly maintained oral hygiene. Poor oral hygiene is associated with a significantly higher score in the presence of tartar, plaque and high IOH. In total patient’s population 67% has amalgam fillings. Presence of amalgam fillings in patients with identified Candida was statistically significant.

Conclusion: This study indicates low level of oral hygiene. Correlation between presence of Candida species and poor oral hygiene was proved. Also Candida was more present among patients with amalgam fillings. Improvement of oral hygiene is necessary for oral health and health in general, as well.

Yeast Advisor: Hg vapors

“Mercury vapors from dental fillings play havoc on the body through a host of means, the least of which is to feed the bacteria, fungi, and yeasts that thrive on mercury. Mercury will promote the growth of Candida, though as it absorbs the mercury, it thereby protects the system to a certain extent from its toxicity – until they are saturated then they begin to re-release the mercury in organic form.”

Yeast advisor’s take

“Mercury fed Candida becomes more and more virulent and eventually penetrates the intestinal walls and invades the cells. These fungal microorganisms become quite at home in the cell, and can easily be considered a principle characteristic of cancer”.

Dr. Sircus could be right because this published study in 2012 found that Candida yeast was 67% more prevalent among patients with amalgam fillings.

Dr. Scott Fogle from Portland Oregon, tackles the question of which comes first, Candida or mercury:

“It is very difficult to say which came first, the yeast buildup or the low-level mercury toxicity. The most prevalent theory is that low-level mercury toxicity causes some degree of suppression of the immune system, making it easier for the yeast to proliferate in the human body. This process is especially true in the gastrointestinal tract and in the vaginas of particularly sensitive women.”

We still don’t know if there is a causal relationship between the Hg contaminated Ag amalgam fillings and Candida infections. The United States would probably be a better place to test such a hypothesis because we have the composite fillings too. Perhaps there is a very deleterious interaction between yeasts and heavy metals

CIP1, Cd2+, not all heavy metals are the same

Hong YM, Park SW, Choi SY. Expression of the CIP1 gene induced under cadmium stress in Candida sp. Mol Cells. 1998 Feb 28;8(1):84-9. free article must click on PDF when arriving at this link

This 1997 paper was a difficult read because it took 10 years for scientists to determine that Cip1 blocks the cell cycle (division) progression. Chang YL et al. Yeast Cip1 is activated by environmental stress to inhibit Cdk1-G1 cyclins via Mcm1 and Msn2/4. Nat Commun. 2017 Jul PMC free article

The next section will present present evidence that Candida species can make sulfide crystals from Cd, Hg, and Pb.

Figures 1-5 of this publication describe molecular techniques used to identify the protein coding and upstream regulatory elements of the CIP1 gene. The message of these figures is that 1mM CdCl2 induces CIP1 expression in a time and concentration dependent manner in a manner in which other heavy metals such as Pb and Hg do not.

We don’t know if the CIP1 response is different because Cd is more toxic than the other two. We are about to learn that these three metals are handled similarly when in comes to making sulfide crystals.

Hg, Cd, Pb in Candida yeasts

Cuéllar-Cruz M, Lucio-Hernández D, Martínez-Ángeles I, Demitri N, Polentarutti M, Rosales-Hoz MJ, Moreno A. Biosynthesis of micro- and nanocrystals of Pb (II), Hg (II) and Cd (II) sulfides in four Candida species: a comparative study of in vivo and in vitro approaches. Microb Biotechnol. 2017 Mar;10(2):405-424.PMC free article

Scanning electron microscopy showing crystals

In very simple terms, four different species of Candida (C. albicans, C. glabrata, C. krusei and C. parapsilosis) were grown in the presence of 1mM Pb2+, Hg2+ or Cd2+

  • The crystals were visualized with scanning electron microscopy (SEM). The extracellular crystals were observed attached to the cell wall (CW). The CW is the outermost structure of Candida and the first to interact with heavy metals.
  • The intracellular crystals were observed like lights inside the yeast, not surprising considering that CdS and PbS are used in LEDs. The paper did not make it clear if the “lights” were colored.
  • All crystals below 1 μm in size are considered nanocrystals (NCs) and larger to this value are considered microcrystals (MCs).
Figure 2
Formation of extracellular and intracellular micro‐ or nanocrystals by Candida species in the presence of Pb2+, Hg2+ or Cd2+.
Control cells (A, E, I, M),
treated with Pb2+ (B, F, J, N),
treated with Hg2+ (C, G, K, O)
treated with Cd2+ (D, H, L, P).
Scale bar is included in each photomicrograph. Arrows indicate the extracellular and intracellular micro‐ and nanocrystals formed in the treated cells with respect to the control cells. All crystals below 1 μm in size are considered nanocrystals and larger to this value are considered microcrystals

Qualitative suggestion that crystals are sulfides

X-ray fluorescence is a qualitative means of assessing the elemental composition of a substance.

X‐ray powder patterns collected on Candida cells.
A. Cells not exposed to heavy metals (controls).
B. Candida cells exposed to Pb2+. Red bars represent expected positions of cubic Fmm PbS.
C. Candida cells exposed to Cd2+. Red bars represent expected positions of cubic F4¯3m CdS.
D. C. glabrata, C. krusei or C. parapsilosis cells exposed to Hg2+.
Red bars represent expected positions of trigonal P3221 HgS

Summary cartoons

Not shown are data for C albicans possible formation of HgCl2 grown in the presences of Hg2+

This is the summary figure of different transporters teh authors think are causing the formation of sulfur containing heavy metal crystals. Is this essentially detoxification of the heavy metals? Or is this supercharged toxicity?

When it comes down to it, this metal sulfide formation is nothing new in the microbial world. Are these metal sulfides toxic? The authors might have been interested in CdS as a component of quantum dots.

Sulfides of Hg, Cd, and Pb


Varmazyari A, Taghizadehghalehjoughi A, Sevim C, Baris O, Eser G, Yildirim S, Hacimuftuoglu A, Buha A, Wallace DR, Tsatsakis A, Aschner M, Mezhuev Y. Cadmium sulfide-induced toxicity in the cortex and cerebellum: In vitro and in vivo studies. Toxicol Rep. 2020 May 6;7:637-648. PMC free article

Bacteria vs synthetic production

Synthesis strategy for nanoparticles of both bacterial and laboratory origin. One wonders if this pathway could occur inside the rat.

Protocol summary

Male Sprague-Dawley rats (n = 30) weighing 210 ± 10 g were randomly divided into 6 groups (n = 5/group). Each rat received 1 dose CdS (0, 0.1, 1, 5, 15 or 25 mg/kg) intraperitoneally. The threshold of toxicity was 0.01 μg/mL. CdS at 0.01 μg/mL did not exert significant toxicity in

  • MTT, (an assay that measures NADH)
  • total antioxidant capacity TAC
  • total oxidant status TOS

Some histology…

  • (A) control group, normal histological image, Below
  • (B) 0.1 mg/kg group, mild hyperemia in the vessels, Hyperemia is increased blood flow. Is blood flowing out more too or is blood just pooling?
  • (C) 1 mg/kg group, hyperemia in the vessels, atrophy in very few neurons (arrow), How does one decide whether any of the “very few” neurons are important?
  • (D) 5 mg/kg groups, severe hyperemia (arrowhead) in the veins, atrophy in the neuron (arrow), In this example of atrophy the rest of the tissue seems to be pulling away from the damaged neuron more.
  • (E) 15 mg/kg groups, moderate atrophy in the neurons (arrow), degeneration and necrosis (arrowhead), hyperemia in the vessels,
  • (F) 25 mg/kg groups, Severe hyperemia of the vessels, severe atrophy of neurons (arrow), degeneration and necrosis (arrowhead) 15 mg/kg groups, moderate atrophy in the neurons

Figure 7 from Varmazyari 2020 H&E, Bar: 20 μm.

The in vivo study revealed that CdS can easily cross the BBB in dose-dependent manner, with signs of degeneration only at doses exceeding 0.1 mg/kg.

Cinnabar and HgS

What is Cinnabar?

According to Wikipedia authors Cinnabar is a largely HgS mineral. Cinnabar, has been used in combination with other agents as a sedative in Traditional Chinese Medicine for over 2000 years.[1] The cinnabar used in this study contained: 97.16% HgS, 1.10% Si, 0.53% Sb, 0.35% Se, 0.30% Ca, 0.22% Fe and 0.16% Na determined by X-ray fluoroscopy) Cinnabar powder was produced by grinding in the presence of de-ionized water in an agate mortar.

Huang CF, Liu SH, Lin-Shiau SY. Neurotoxicological effects of cinnabar (a Chinese mineral medicine, HgS) in mice. Toxicol Appl Pharmacol. 2007 Oct 15;224(2):192-201. PubMed

Cinnabar mouse experiments

Male and female mice were given HgS at a clinical dose of 10 mg/kg/day for 3-11 weeks.

  • HgS was significantly absorbed by gastrointestinal tract and transported to brain
  • Spontaneous locomotor activities was suppsressed in male but not female mice.
  • Frequencies of jump and stereotype-1 episodes were progressively decreased after 3-week oral administration in male and female mice.
  • Pentobarbital-induced sleeping time was prolonged and the retention time on a rotating rod (60 rpm) was reduced after treatment with cinnabar for 6 weeks and then progressively to a greater extent until the 11-week experiment.
  • In addition, the biochemical changes in blood and brain tissues were studied; the inhibition of Na(+)/K(+)-ATPase activities, increased production of lipid peroxidation (LPO) and nitric oxide (NO) were found with a greater extent in male mice than those in female mice.

HgS (insoluble) vs HgCl2 (soluble)

Wang Q, Yang X, Zhang B, Yang X, Wang K. Cinnabar is different from mercuric chloride in mercury absorption and influence on the brain serotonin level. Basic Clin Pharmacol Toxicol. 2013 Jun;112(6):412-7. free paper

Two sets of experiments were carried out. For comparison with soluble HgCl2, male C57BL/6J mice were treated by oral administration of various doses of cinnabar suspended in 0.5% carboxymethyl cellulose (CMC) (0.01, 0.05, 0.1 and 1 g/kg) once per day for 10 consecutive days, while 0.5% CMC was used for the vehicle control and 0.01 g/kg of HgCl2 was used for contrast.

Previous work from this group postulated that dissolved components of cinnabar in intestinal environment may include Hg(SH)+, HgS(OH)−, HgS2(OH)− and HgS3(OH)−, and dissolving components of cinnabar in the gastric environment are probably related to Hg2SOH+. They also postulated that Hg polysulfides in the GI tract. The also claim a high level of permeability of Hg polysulfides.

For comparison with insoluble HgS, male C57BL/6J mice were administered cinnabar (0.1 g/kg, po) once per day or pure HgS (0.1 g/kg, po) or vehicle (0.5% CMC, po) for 10 consecutive days.

GroupSerum (ng/ml)Brain (ng/g)Liver (ng/g)Kidney (ng/g)
Vehicle1.39 ± 0.052.96 ± 1.2411.19 ± 4.3114.24 ± 2.97
HgCl2 0.01 g/kg401.94 ± 30.3**190.25 ± 11.8**5571.91 ± 1211**23592.40 ± 446**
Cinnabar 0.01 g/kg4.10 ± 0.4710.63 ± 2.53*25.58 ± 5.9770.00 ± 18.02
Cinnabar 0.05 g/kg14.63 ± 0.59**11.07 ± 2.10*32.73 ± 6.9682.69 ± 20.02
Cinnabar 0.1 g/kg26.75 ± 6.98**12.20 ± 1.44*84.75 ± 9.47271.10 ± 49.25
Cinnabar 1 g/kg75.30 ± 9.24**13.27 ± 2.22*89.47 ± 10.02455.88 ± 76.93
Table 1. Mercury contents after cinnabar and HgCl2 administration for 10 days All data are presented as mean ± S.E.M. (n = 12 for each group).*< 0.05, **< 0.01 as compared with vehicle control

Cinnabar vs pure HgS, nurotransmitters too

Then we get to Cinnabar that was indistinguishable from pure HgS…

GroupSerum (ng/ml)Brain (ng/g)Liver (ng/g)Kidney (ng/g)
Vehicle1.52 ± 0.021.83 ± 0.495.71 ± 1.6916.29 ± 1.19
Cinnabar 0.1 g/kg24.62 ± 1.55**12.12 ± 1.19*77.57 ± 10.17**206.21 ± 33.76**
HgS 0.1 g/kg27.44 ± 3.29**8.03 ± 1.98*41.39 ± 9.78**454.56 ± 70.68**
Table 2. Mercury contents after cinnabar and HgS administration for 10 days. All data are presented as mean ± S.E.M. (n = 10 for each group).*< 0.05, **< 0.01 as compared with vehicle control.

This cinnabar/HgS acts as a sedative, what does it do to neurotransmitters?

While the authors were perhaps most interested in understanding TCM, these rsults are interesting from the standpoint of “what if our oral or other microflora are making HgS”?

Vehicle26.87 ± 3.3919.09 ± 1.8122.82 ± 2.8450.08 ± 5.1418.02 ± 2.2820.06 ± 1.97
HgCl2 0.01 g/kg25.01 ± 1.7617.26 ± 2.7022.24 ± 1.4147.07 ± 5.5218.61 ± 3.7517.96 ± 2.33
Cinnabar 0.01 g/kg26.11 ± 2.2717.74 ± 1.9923.22 ± 2.5349.39 ± 4.2319.52 ± 3.3217.98 ± 2.42
Cinnabar 0.05 g/kg24.73 ± 1.51*19.06 ± 2.2921.61 ± 2.8456.38 ± 5.1017.73 ± 3.3918.40 ± 2.69
Cinnabar 0.1 g/kg22.29 ± 2.67**17.60 ± 2.1421.74 ± 2.19*44.78 ± 7.7322.45 ± 3.2216.50 ± 1.52
Cinnabar 1.0 g/kg21.54 ± 2.24**17.18 ± 3.3420.29 ± 1.1947.23 ± 5.3519.50 ± 3.3515.74 ± 2.51
Table 3. Effects of cinnabar and HgCl2 on monoamine neurotransmitter levels (ng/g/wet weight) All data are presented as mean ± S.E.M. (n = 12 for each group). *< 0.05, **< 0.01 versus vehicle control.

Then cinnabar and HgS might not be one in the same

Vehicle34.75 ± 5.6710.42 ± 2.5115.33 ± 4.0155.61 ± 12.1510.29 ± 1.5410.97 ± 1.58
Cinnabar 0.1 g/kg26.43 ± 3.83a12.77 ± 1.6615.81 ± 2.9651.16 ± 5.7112.43 ± 2.5611.88 ± 1.37
HgS 0.1 g/kg28.72 ± 2.53a10.75 ± 0.5814.95 ± 2.4954.06 ± 3.1510.56 ± 1.3410.32 ± 0.74
Table 4. Effects of cinnabar and HgS on monoamine neurotransmitter levels (ng/g/wet weight) All data are presented as mean ± S.E.M. (n = 10 for each group).a < 0.05 versus vehicle control.


Cao Y, Wang D, Li Q, Liu H, Jin C, Yang J, Wu S, Lu X, Cai Y. Activation of Nrf2 by lead sulfide nanoparticles induces impairment of learning and memory. Metallomics. 2020 Jan 29;12(1):34-41. PubMed free article

sizing up nanoparticles

Like CdS, Lead sulfide nanoparticles (PbS NPs) are semiconductor materials that are also used in LEDs and quantum dots. that have been widely applied to light-emitting diodes (LEDs),

An image of PbS NP used in this study. ,

Dosing protocol and the Morris water maze

Male mice were intragatrically injected with Pb NP five days per week for six weeks.

  • controls
  • low exposure (25 mg kg1 PbS NPs)
  • medium exposure (50 mg kg1 PbS NPs)
  • high exposure (100 mg kg1 Pb NP)

The Morris water maze measures spacial memory and the first sign of neurological dysfunction in these rats.

ig. 2 Escape latency (A), time of first reaching the platform (B), objective quadrant time (C), and number of rats crossing the platform (D)

Of course there is Pb in the hippocampus of these rats.

The really notable thing is that the concentration in the hippocampus is almost as high as in the blood.

Changes in enzymes

Three key anti-oxidant enzymes take a hit in the hippocampus of these rodents. There’s a increase in the lipid oxidation product MDA too.

Fig. 4 Concentration results of the SOD, GSH-Px, CAT, and MDA analysesfrom the hippocampi of the mice that received PbS NPs (* compared withcontrol group P o 0.05)

GSH and GSH synthesis related enzymes take a hit to. The apoptosis rate also increases

Fig. 5 Concentrations of GSH (A), GR (B), and GCS (C) in the hippocampi of the mice that received PbS NPs, and the apoptosis rates of thegroups (D) (* compared with control group P o 0.05).

Flow cytometry images were shown in Figure 6 to give a visual image of cells in apoptosis. Figure 7showed TUNEL stain images.to provide a visual documentation of DNA fragmenation that is part of apoptosis. Figures 8 and 9 showed some transmission electron micrographs of hippocampi from PbS treated rats. The authors claimed damage to synapses in addition to just the cells.

The antioxidant transcription factor NRF2 is activated by injury and inflammation. It binds to the antioxidant response element (ARE) that is upstream for genes that code for antioxidant defense enzymes. NRF2 can increase its own mRNA and protein levels too in a feed forward fashion.

Fig. 10 Expression levels of the mRNAs of Nrf2, HO-1g-GCS, and GPx-1in the hippocampi of the different groups.

Transcriptional regulation

Good researchers do not stop at measuring protein mRNA transcripts. They also use Western blotting to confirm that these transcripts are successfully translated into protein.

Fig. 11 Expression levels of the proteins of Nrf2, HO-1g-GCS, and GPx-1in the hippocampi of the different groups.


To tie up the metal sulfide section of this post, CdS, HgS, and PbS get into the brain. How much of these metal sulfides come into existence via microbial action, by Candida remains to be established.

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